DE69329147T2 - ANALYSIS CUFF WITH A LOW DOUBLE BREAKAGE - Google Patents

Description

This application is a continuation-in-part of US patent application Ser. No. 07/859,218, filed March 27, 1992, the contents of which are incorporated herein by reference.

Field of invention

The present invention relates to analysis cuvettes for the analysis of liquid samples to be examined. In particular, the present invention relates to plastic analysis cuvettes which have a low birefringence for the analysis of a liquid sample to be examined in analytical systems.

Background of the invention

To meet the increasing demand of modern clinical laboratories to provide cost-effective services, which requires reducing operating expenses such as laboratory costs and material costs, the dependence on low-cost, disposable materials has increased. In addition, the use of automated clinical analyzers has also increased, improving the efficiency of laboratory procedures by reducing the number of tasks the operator has to perform.

The analysis of a test sample generally involves the direct analysis of the test sample, or involves the reaction of the test sample with one or more reagents related to one or more analytes, wherein a reaction mixture comprising the test sample and one or more reagents is formed either manually or by an automated device. Generally, the test sample or reaction mixture is then stored in a cuvette and read or otherwise analyzed by an analytical system or device related to one or more characteristics of the test sample. In the case of an absorbance assay or a fluorescence polarization assay for For example, to determine the presence of a volume of analyte in a test sample, the absorbance or fluorescence polarization response of the reaction mixture, respectively, in a reaction cuvette are measured by the instrument and, if an analyte is present, correlated with its presence or amount in the test sample. Analysis of a test sample or reaction mixture is usually performed by directing a beam of light or other energy source into or through an optically readable region of a cuvette containing the test sample or reaction mixture, after which the resulting response is detected or measured.

To provide a quick turnaround time and prevent cross-contamination of test samples, the cuvettes are used for a single analysis and then discarded. Various analytical cuvettes for the analysis of samples under investigation have been described. In most cases, reaction cuvettes made of glass are used for such analyses due to the physical properties of glass that allow reproducible and accurate results and are required to perform various analyses, particularly absorbance assays and fluorescence polarization assays. However, the manufacture of glass reaction cuvettes is expensive and increases the cost of performing the analysis if the cuvette is only used for a single analysis and then discarded. In addition, breakage of the glass during loading or handling by a technician or processing by an instrument can cause injury to the technician or operator or damage the instrument used to perform a particular analysis. Since it is therefore desirable to use disposable reaction cuvettes that are inexpensive to manufacture to reduce such costs and that are durable during loading and handling by a technician or operator of an instrument, plastic analysis cuvettes have also been described. Although plastic analysis cuvettes have been described previously, such plastic cuvettes may give false results if they have unsuitable optical properties such as exhibit high birefringence. To overcome such unsuitable optical properties, plastic analytical cuvettes that are embossed during the molding process have been described. However, in order to enjoy the benefits of the embossing process, such a molding process is only practical in the manufacture of generally square or rectangular cuvettes. In addition, such square or rectangular analytical cuvettes are not readily applicable in modern analytical instruments. The plastic analytical cuvettes such as the Abbott Spectrum® Multicuvette and the Abbott VP® Multicuvette, for example, exhibit a level of birefringence that exceeds that required when running a sample with a glass cuvette (e.g., the requirements of the Abbott Tdx® analyzer).

JP-A-01 202417 teaches a blood collection line that is compression molded from a colorless, transparent and hard plastic material. JP-A-01 202417 provides a compression mold having a mold cavity with an upper and a lower end, and includes the steps of: injecting the molten plastic material at the lower end of the mold cavity; and allowing the molten plastic material to substantially solidify.

US-A-4 381 275 describes a process for the stabilized core injection molding of plastic. The process is carried out by controlling a plurality of constriction openings arranged around the mold.

US-A-4 994 220 teaches a method for injection molding injection molded parts of a plasticized liquid crystal polymer material using at least two spaced apart inlet openings. US-A-4 994 220 does not include any teaching relating to analysis cuvettes.

US-A-4 898 529 describes an apparatus for molding magneto-optical substrates and emphasizes that horizontal molds have the advantage over vertical molds in that polarization noise is reduced.

US-A-4 126 291 discloses a method for injection molding. The molded product of US-A-4 126 291 is not a cuvette and US-A-4 126 291 also fails to address, either explicitly or implicitly, the problem of birefringence.

JP-A-4 135820 relates to a tube having a bend-free bottom with a uniform cross section. The tube is manufactured by pouring molten molding material into an annular gap part of the tube through side discharge gaps at an upper part of the tube in the state that the gas and the molten molding material are discharged through a thin hole.

In order to meet the growing demands of clinical laboratories to reduce the cost of various analyses performed on a daily basis in large quantities while providing accurate results, there is a need to provide reaction cuvettes that are disposable and have the desired optical properties for use in a variety of analyses.

Summary of the invention

According to the present invention, there is provided a method of manufacturing such plastic analysis cuvettes as defined in claims 1-12. In particular, the optical properties of the plastic analysis cuvettes are the same as the optical properties of glass, providing low birefringence across their optical reading range. Preferably, the plastic analysis cuvette is substantially cylindrical, with a closed, round bottom which does not require any orientation other than top-to-bottom when performing particular analyses.

When used for the analysis of a test sample or reaction mixture thereof, the plastic cuvette of the present invention provides accurate and reproducible results while providing inexpensive, disposable analysis cuvettes that can be used instead of conventional glass analysis cuvettes when different analytical procedures that require optical measurements are carried out. The plastic analysis cuvette is particularly useful for carrying out fluorescence polarization and extinction assays.

Short description of the drawings

Figure 1 is an isometric view of an automated analytical system described herein, showing the system chassis, a suspended carousel at the front end, a computer screen, and a keyboard;

Fig. 2 is an isometric view of an automated analytical instrument rack and enclosure;

Fig. 3 is a top plan view of the automated analytical system with the component covers removed to show the automated analytical system equipment in detail and relative position;

Fig. 4 is an elevational view of the automated analytical system and a partial section of the front end carousel elements;

Figures 4A and 4B illustrate a perspective side elevation and a partial end view of a reagent pack and a reagent pack cover means for use with the automated analytical system;

Fig. 5 is an isolated top view and partial section of the drive and guide elements of the front end carousel of the automated analytical system, with the same removed;

Figure 6 is a cross-sectional side view of an isolated process carousel of the automated analytical system with two reaction vessels enclosing a plastic analysis cuvette of the present invention in place, one of which is positioned for an FPIA reading;

Fig. 7 is an isometric view of the sample, sample arm and pipette of the isolated automated analytical system;

Fig. 8 is a schematic side view of the sample arm wiring and sensor means of the automated analytical system;

Fig. 9 is a cross-sectional side elevation view of an automated bladder irrigation syringe device of the automated analytical system;

Fig. 9A is an isolated cross-sectional side view of the syringe bore end portion of the automated bladder flush syringe with the reciprocating piston near the end of travel toward the bore end portion;

Fig. 9B is an isolated cross-sectional end view of the plunger and bore of the automated bladder flush system syringe taken along line 9B-9D;

Figures 10 and 10A illustrate, respectively, a planar top view of a reaction vessel and a side view of the reaction vessel for use with the automated analytical system, with the reaction vessel compartments marked where required for FPIA processing and including a plastic analysis cuvette according to the present invention;

Figures 108 and 100 illustrate a top plan view and a side view, respectively, of the reaction vessel being marked and fed for MEIA processing;

Fig. 11 is a cross-sectional side view of the transfer element of the automated analytical system engaging a reaction vessel for transfer from the main carousel to the transfer site;

Fig. 12 is a side elevational perspective view of the transfer system of the automated analytical system;

Fig. 13 is a cross-sectional plan view illustrating in isolation the controlled environment region of the automated analytical system;

Fig. 14 is a partial plan view of the lower housing of Figs. 1 and 2, illustrating both a water and/or buffer supply location and liquid and solid waste containers of the automated analytical system;

Fig. 15 is a schematic view illustrating the controlled system ambient air flow and temperature control of the automated analytical system;

Fig. 16 is a side elevational view, partially in section, of a MEIA cartridge for use with the automated analytical system;

Fig. 17 is a cross-sectional side elevation of a MEIA cartridge feeder of the automated analytical system;

Figure 18 is an isolated cross-sectional side view of the MEIA cartridge feeder alignment bolt mechanism of the automated analytical system;

Figure 19 is an isolated cross-sectional side view of the MEIA cartridge ejector of the automated analytical system;

Fig. 20 is a functional block diagram of the optical signal processor of the automated analytical system;

Fig. 21 is a schematic view of the FPIA optical system of the automated analytical system:

Figure 22 is a schematic view of the FPIA read(r) sequence of the automated analytical system;

Figure 23 is an isolated cross-sectional side view of a MEIA cartridge carousel of the automated analytical system, a MEIA cartridge, and a MEIA reader;

Fig. 24 is a schematic view of the MEIA optical system layout of the automated analytical system;

Figure 25 is a schematic view of the MEIA reading sequence of the automated analytical system;

Fig. 26 is a schematic reaction sequence of an FPIA for T4 performed on the automated analytical system ;

Figure 27 is a schematic reaction sequence of a single-step sandwich MEIA performed on the automated analytical system;

Figure 28 is a schematic reaction sequence of a two-step sandwich MEIA performed on the automated analytical system;

Fig. 29 illustrates a mold and core pin used to manufacture the plastic analysis cuvette according to the method of the present invention;

Fig. 30 illustrates the equivalence of the plastic cuvettes of the present invention with the glass cuvettes by comparing the millipolarization (mP) averages of the plastic cuvettes of the present invention with the mP averages of the glass cuvettes;

Figure 31 illustrates the equivalence of the plastic cuvettes of the present invention to the glass cuvettes by comparing the ratio of the mP averages of the plastic cuvettes of the present invention to the mP averages of the glass cuvettes;

Figure 32 illustrates the comparison of the FPIA calibration curves for C-reactive protein (CRP) performed on an Abbott Tdx® analyzer using the plastic analysis cuvette of the present invention with a glass analysis cuvette;

Figure 33 illustrates the comparison of the FPIA calibration curves for opiate performed on an Abbott Tdx® analyzer using the plastic analysis cuvette of the present invention versus a glass analysis cuvette;

Figure 34 illustrates the comparison of theophylline FPIA calibration curves performed on an Abbott Tdx® analyzer using the plastic analysis cuvette of the present invention versus a glass analysis cuvette;

Figure 35 illustrates the comparison of absorbance linearity for glucose performed on an Abbott VP® analyzer using the plastic analysis cuvette of the present invention versus a glass analysis cuvette;

Description of the invention Definitions

The following definitions are applicable to the present invention:

The term "birefringence" as used herein refers to the degree of retardation of an extraordinary ray from an energy beam, such as a beam of light, as it passes through a material into which the energy beam has been directed. The greater the degree of retardation, the greater the level of birefringence of the extraordinary ray will be.

The term "optical reading region" as used herein refers to the region of the plastic analysis cuvette of the present invention into which an energy source is directed and from which such energy source or a portion thereof is emitted, preferably the lower region of the analysis cuvette described herein.

The term "test sample" as used herein refers to a material whose physical properties or chemical properties are to be analyzed. The test sample can be used as obtained from the source, directly or following pretreatment to modify the sample character. The test sample can be derived from any biological source such as a physiological fluid including blood, saliva, ocular lens fluid, cerebral spinal fluid, sweat, urine, milk, ascites fluid, rude synovial fluid, peritoneal fluid, amniotic fluid, or the like. The test sample can be pretreated prior to use, such as preparing plasma from blood, diluting viscous fluids, or the like; treatment procedures can include filtration, distillation, concentration, inactivation of interfering components, and addition of reagents. In addition to physiological fluids, other liquid samples such as water, food products, and the like may be used to perform environmental or food product assays. In addition, a solid suspected of containing the analyte may be used as the test sample. In some cases, it may be beneficial to modify a solid test sample to be assayed to form a liquid medium or to release the analyte.

The term "analyte" or "analyte of interest" as used herein refers to a compound or composition to be detected or measured that has at least one epitope or binding site. The analyte can be any substance for which a naturally occurring binding moiety exists or for which a binding moiety can be prepared. Analytes include, but are not limited to, limited - toxins, organic compounds, proteins, peptides, microorganisms, amino acids, nucleic acids, hormones, steroids, vitamins, drugs (including those administered for therapeutic purposes and those administered for prohibited purposes), viral particles, and metabolites of or antibodies to any of the above substances. More specifically, such analytes include, but are not intended to be limited to, ferritin; creatine kinase MIB (CK-MB); digoxin; phenytoin; phenobarbitol; carbamazepine; vancomycin; gentamicin; theophylline; valproic acid, quinidine; luteinizing hormone (LH); follicle stimulating hormone (FSH); estradiol, progesterone; IgE antibodies; vitamin B2 microglobulin; glycine hemoglobin (Gly. Hb); cortisol; digitoxin; nacetylpocainamide (NAPA); Procainamide, antibodies for rubella such as rubella IgG and rubella IgM; antibodies for toxoplasmosis such as toxoplasmosis IgG (Toxo-IgG) and toxoplasmosis IgM (Toxo-IgM); testosterone; salicylates; acetaminophen; hepatitis B virus surface antigen (HBsAg); antibodies for hepatitis B core antigen such as anti-hepatitis B core antigen IgG and IgM (anti-HBC); human immunodeficiency virus 1 and 2 (HIV 1 and 2); human T-cell leukemia virus 1 and 2 (HTLV); hepatitis B e antigen (HBeAg); antibodies for hepatitis B e antigen (anti-HBe); thyroid stimulating hormone (TSH); thyroxine (T4); total triiodothyronine (total T3); free trilodothyronine (Free T3); carcinoembryonic antigen (CEA); and alpha-fetal protein (AFP). The term "analyte" also includes any antigenic substances, haptens, antibodies, macromolecules and combinations thereof.

The term "analyte analogue" as used herein refers to a substance that cross-reacts with an analyte-specific binding moiety, although it may do so to a greater or lesser extent than the analyte itself. The analyte analogue may include a modified analyte as well as a fragmented or synthetic portion of the analyte molecule, provided that the analyte analogue shares at least one epitope site with the analyte of interest. An example of an analyte analogue is a synthetic Peptide sequence that duplicates at least one epitope of the entire molecular analyte so that the analyte analogue can bind to an analyte-specific binding moiety.

The term "binding member" as used herein refers to a member of a binding pair, i.e., two different molecules wherein one of the molecules specifically binds to the second molecule by a chemical or physical means. In addition to the antigen and antibody binding pair members, other binding pairs include, for example, without limitation, biotin and avidin, carbohydrates and lectins, complementary nucleotide sequences, complementary peptide sequences, effector and receiver molecules, enzyme cofactors and enzymes, enzyme inhibitors and enzymes; a peptide sequence and an antibody specific for the sequence of the entire protein, polymer acids and bases, dyes and protein binding agents, peptides and specific protein binding agents (e.g., ribonuclease, S-peptide and ribonuclease S-protein), and the like. In addition, the binding pairs may include members that are analogs of the original binding member, e.g., an analyte analog or a binding member prepared by recombinant techniques or molecular processing. When the binding member is an immunoreactant, it may be, for example, a monoclonal or polyclonal antibody, a recombinant protein or antibody, a chimeric antibody, a mixture(s) or residue(s) of the foregoing, as well as a preparation of such antibodies, peptides and nucleotides, the suitability of which for use as binding members is known to those skilled in the art.

The term "detectable moiety" as used herein refers to any compound or conventionally detectable chemical group that has a detectable physical or chemical property and that can be used to label a linker to form a conjugate therewith. Such a detectable chemical group may include, but is not intended to be limited to, enzymatically active groups such as enzymes, enzyme substrates, prosthetic groups or coenzymes; spin labels; fluorescent agents and fluorophores; chromatophores and chromogens; luminescent agents such as chemiluminescent agents and bioluminescent agents; specifically bindable ligands such as biotin and avidin; electroactive species; radioisotopes; toxins; drugs; haptens, DNA; RNA; polysaccharides; polypeptides; liposomes; colored particles and colored microparticles; and the like.

The term "continuous access" as used herein refers to the ability to add additional test samples or reagents to the automated analytical system described herein without interrupting the assays being performed by the automated analytical system at the time of addition.

The term "random access" as used herein refers to the ability of the automated analytical system described herein to simultaneously perform more than one scheduled assay in any order in which such plurality of scheduled assays are presented to the automated analytical system described herein.

The term "simultaneous" as used herein refers to the ability of the analytical system automated herein to independently perform two or more scheduled assays at the same time.

The term "kitten" as used herein refers to the ability of the automated analytical system described herein to produce a disposable unit dose by separately transferring test samples and reagents to the reaction vessel described herein without initiating an assay reaction sequence.

The term "quat" refers to a polycation material solution for assays.

The term "flexible protocol" refers to a variety of different assay protocols capable of being processed in accordance with the inventive system. Examples include MEIA formats arranged in one- and two-step sandwich and competitive assay formats; the order of activity treatment including the ability to begin sample processing for both MEIA and FPIA formats at the front end carousel prior to transfer to the process carousel; variable incubation periods; optical reading formats and wash sequences. This is in contrast to some known prior art random access systems which force all assay protocols to maintain a strict "lock-step" format in which the assay order (ie, 1- versus 2-step formats), activity order, incubation timing and other similar protocols are set by the instrument.

Plastic analysis cuvette

The plastic analysis cuvette of the present invention provides essential optical properties for performing various analytical methods known in the art. In particular, the optical properties of the plastic analysis cuvette of the present invention are generally the same or identical to the optical properties of glass analysis cuvettes, wherein the degree of retardation of an exceptional beam or energy beam, such as a beam of light, passing through the analysis cuvette is minimal, thereby substantially preventing any change in the polarization state or other state of the light passing through the cuvette wall or walls - particularly through its optical reading region. As would be understood by one skilled in the art, the retardation of an energy source, such as a beam of light, directed into a material depends on the magnitude and direction of the induced stress of such material. For example, passing a beam of linearly polarized light through a material having an induced stress will result in a change in the polarization state of the beam. Accordingly, in order for an analytical cuvette to be acceptable for analytical measurements that require optical measurements such as absorbance and fluorescence polarization measurements, it is important that the cuvette is prepared under conditions that deliver the lowest possible voltage.

The analytical cuvette of the present invention is manufactured by injection molding using an injection molding machine known in the art and an analytical cuvette mold having the shape of the analytical cuvette. In general, plastic injection molding is a process by which the plastic material is melted and injected into a mold cavity. Once in the mold, the molten plastic cools to a shape that reflects the cavity. The resulting shape is usually a finished product that requires little or no additional steps before use. The injection molding process is accomplished with an injection molding machine that generally includes an injection unit to melt the plastic material into the mold and transfer it into the mold, and a clamping unit to hold the mold in firm resistance to the injection pressure and for removal of the molded material.

Typically, the injection unit melts the plastic before it is injected into the mold, after which it injects the melt into the mold at a controlled pressure and rate. Different injection unit configurations that may be used are a screw preplasticator, known as a two-stage unit, and the reciprocating screw machine. A screw preplasticator uses a plasticizing screw (first stage) to feed the molten plastic to an injection piston (second stage). The reciprocating injection unit melts and injects the plastic material without a piston, with powdered or pelletized plastic being melted from a hopper and transferred by the rotating screw into a screw tip check valve. The plastic flows through the screw tip and is deposited at the front of the screw, wherein the buildup of plastic at the front of the screw forces the screw toward the rear of the injection unit. The screw rotation, melt accumulation and backward movement continues until the shot is made. During the following machine cycle, the screw tip check valve closes to prevent the plastic material from flowing back along the screw, and the screw tip and feed screws function as an injection piston that forces the plastic melt into the mold. Conductive heat supplied by a barrel temperature and mechanical heat generated by the screw rotation both contribute to the processing of a good quality melt. In this connection, mixing of the plastic between screw flights occurs as the screw rotates, shearing the molten surface from the plastic melt. Accordingly, such mixing and shearing action is repeated as the plastic material moves along the screw until the plastic melt is completely melted.

As would be understood by those skilled in the art, plastic materials consist of polymer chains that are normally long and usually in a random state, especially in the case of an amorphous polymer. Accordingly, during the injection molding process, the plastic material is forced through a very small orifice at a rapid flow rate, such a process tends to align the long polymer chains of the plastic material, thereby introducing stress into the molten product. When transparent or translucent plastics are used to mold such materials, the introduced stress affects the birefringence of the resulting molded part or component.

In order to maintain the polarization state or other optical state of a photon passing through the optical reading region of the analysis cell, the injection molding process according to the present invention is carried out under conditions that provide an analysis cell of the present invention having favorable optical properties. The present inventors have unexpectedly and surprisingly found that a plastic material which is a location in the assay cell mold that is a substantial distance away from the optical reading region of the assay cell, results in minimal stress to provide favorable optical properties in the optical region. In addition, the present inventors have found that such minimal stress is achieved by admitting the plastic material into the mold at at least two locations, preferably on approximately opposite sides of the upper portion of the assay cell. As the plastic material flows away from the outflow gap(s), it begins to approach laminar flow wherein any stress is gradually relieved until solidification occurs and the molecular stress is substantially eliminated. Accordingly, when the plastic material is admitted as described herein, the molecules of the plastic material are provided such that they have a greater chance of becoming substantially stress free before the plastic material solidifies; when the plastic material is let in at more than one location, the flow through each outflow gap is reduced, thereby reducing the level of stress level of the plastic material, while at the same time filling the mold at the same rate, thereby providing an optical reading region having low birefringence towards the lower region of the analysis cell.

In particular, in Fig. 29, there is shown a mold assembly 500 comprising a mold 502 and a mold core 504 for producing a plastic analysis cell 506 according to the method of the present invention. The mold 502 receives the mold core 504 to form therebetween a mold cavity 508 having the desired shape and dimensions of the analysis cell 506. The injection molding method according to the present invention includes the steps of injecting a plastic material melt at the upper end 510 of the mold cavity 508. Although the injection of the plastic material melt at one or the other of the discharge gaps 512 and 514, injection is preferably performed generally simultaneously at discharge gaps 512 and 514 to thereby reduce the induced stress in optical reading region 516 as described above. Once a suitable period of time has elapsed for the plastic material to solidify, mold core 504 is separated from mold 502 and plastic analysis cuvette 506 is removed. It should be understood that although discharge gaps 512 and 514 are shown as being substantially opposite one another, discharge gaps 512 and 514 may be positioned at various locations around upper end 510 of mold cavity 508, and additional discharge gaps may be interposed at various locations therebetween.

Various considerations for injection molding the analysis cuvette according to the present invention to provide minimum stress include such parameters as the amount of time required to inject the plastic material into the mold (injection time); the amount of time during which pressure is applied to the plastic melt material (hold time); the temperature at which the plastic material is injected; the temperature of the mold assembly 500 (mold temperature); the temperature of the plastic melt material in the mold (melt temperature); the pressure at which the plastic material is injected (injection pressure); the pressure at which the plastic material is held in the mold 502 and mold core 504 (hold pressure); the nature and density of the melt; and the particular plastic material used. According to the present invention, the plastic material is preferably a plastic material that has high flow properties. Such plastic materials include, but are not intended to be limited to, acrylic, polystyrene, styrene acrylonitrile, polycarbonate and similar plastic materials.

According to a preferred embodiment of the present invention using acrylic, the injection time is preferably between about 0.90 and 1.40 seconds, the hold time is preferably between about 1.75 and 2.25 seconds, the Injection pressure is preferably between about 896.3188 x 10⁴ Pa (1,300 pounds per square inch (PSI)) and about 1103.1616 x 10⁴ Pa (1600 PSI), the holding pressure is preferably between about 50% of the selected injection pressure to about 80% of the selected injection pressure, the melt temperature is preferably between about 215.55°C (420°F) and about 237.77°C (460°F), the temperature of the mold cavity 508 is preferably between about 37.77°C (100°F) and about 59.99°C (140°F), and the temperature of the mold core 504 is preferably between about 15.55°C (60°F) and about 37.77°C (100°F). It should be understood that a plastic analysis cell according to the present invention may be made with other plastic materials by one skilled in the art familiar with the foregoing considerations. Although the preferred shape of the analysis cell described herein is generally cylindrical and has dimensions as shown in the figures hereof, it should be understood that other shapes and dimensions desired for a particular optical measurement or for adaptation to an analysis cell holder of a particular instrument - such as rectangular, square, and the like - are contemplated.

Analytical systems

The assay cuvette of the present invention can be used in various analytical systems known in the art, such as automated immunoassay analyzers such as the Abbott IMx® analyzer and the Abbott Tdx® analyzer (Abbott Laboratories, Abbott Park, Illinois, USA), which employ methods that involve a variety of different analytical steps, but usually rely on the detection and measurement of optical changes in a reaction mixture during the assay process. For example, a number of well-known methods include single or multi-wavelength fluorescence, fluorescence polarization immunoassays (FPIA) using homogeneous immunoassay methods, microparticle enzyme immunoassays (MEIA) using heterogeneous immunoassay methods, and the like. MEIA technology such as that of the Abbott IMx® Analyzer is used for high and low molecular weight analytes that require greater sensitivity, and FPIA technology, such as that used by the Abbott Tdx Analyzer, is used primarily for lower molecular weight analytes. A front surface fluorometer is used to quantify a fluorescent product generated in the MEIA assays, while an optical fluorescence polarization system is used to quantify the extent of binding of an indicator that binds with the antibody in the FPIA assays. Test samples are automatically processed in the Abbott IMx® Analyzer and the Abbott Tdx® Analyzer by a robotic arm with a pipetting probe and a rotating carousel that positions the samples for processing. These instruments are compact, benchtop analyzers that provide fully automated immunoassay testing capabilities for both routine and specialized immunoassays without any intermediary. These non-isotopic methods eliminate the disposal problems related to radioactivity and increase the shelf life of the reagent while meeting the diverse needs of a variety of assays.

The Abbott IMx® analyzer and Abbott Tdx® analyzer, often referred to as batch analyzers, allow for the analysis of multiple samples and provide access to the test samples for formation of subsequent reaction mixtures. Another common feature of currently available sequential and random access analyzers is the inclusion of various reagents within the instrument itself or near the instrument for pipetting purposes. Liquid reagents, in large quantities, are selected for different types of tests to be performed on the test sample and stored within or near the instrument. Reagent delivery units such as pumps and the like are included in these automated analyzers along with valves, control and pipetting mechanisms so that various reagents are mixed according to the type of test being performed. The Abbott IMx® The analyzer automatically performs all the steps required for the analysis of the test samples and includes numerous checks of the auxiliary systems to ensure that the assay can be completed and the results are valid. The quantitative determination of fluorescence intensity in the MEIA method and polarization in the FPIA method, as well as the final data reduction, are also fully automated on the analyzer. The results are printed by the analyzer and can be accessed from a laboratory computer using a suitable means of automated data collection.

The automated analytical device for conducting homogeneous samples, detecting the precipitate formed by the reaction between the antigens and antibodies in a test sample cell to form light scattering sites, and the methods and device for detecting immunological agglutination reactions are also known in the art in which the analytical cuvette of the present invention can be used. Such device and methods include, for example, the steps of measuring the light absorption of the liquid medium containing antibodies before and after the antigen-antibody reaction by using the light that can be absorbed by the antibodies and calculating the difference in the absorptions. In this way, the presence or absence of the agglutination can be detected based on the fact that the agglutination reaction reduces the concentration of the antibody that affects the light absorption of the liquid medium. As is typical for the procedures and equipment used to process homogeneous samples, these procedures do not require separation of a solid phase from the reaction mixture for further analysis.

Heterogeneous assays are also known by using a sample analyzer to quantitatively determine relatively small amounts of clinically important compounds in a liquid sample to be examined by focusing a light source onto the sample in such a way that, for example, the fluorescent particles in the sample create fluorescence conditions whose strength is a function of the light beam intensity and the concentration of fluorescent particles in the sample. A detector samples the photons that form the fluorescence emissions of the particles when they are excited by the light beam. The introduction of a solid phase material into the sample requires subsequent separation of the solid phase from the reaction mixture for further analysis and before the fluorescence emissions can be detected and measured.

The analytical cuvette of the present invention is particularly useful in relation to a continuous and random access analytical system device as described below and shown in the figures thereof. Such an analytical system device comprises a front end carousel assembly including a sample cup carousel, a reagent pack carousel and a reaction vessel carousel capable of holding a plurality of reaction vessels concentrically mounted and serviced by a transfer pipetting means to form a kit and/or to mix reagents with the sample. The reaction vessel includes a number of reagent holding and mixing containers and a plastic analytical cuvette of the present invention. The kitted and pipetted reaction vessels are transferred by means of a transfer station which provides a means for transferring the kitted and pipetted reaction vessels to a processing work station which in turn includes a controlled environment for maintaining temperature and for timing the mixing of the reagents and for incubation. At least two assay processing devices are provided which are provided for the various samples and kitted reagents in a disposable unit dose means for analyzing the incubated reaction mixtures. The disposable unit dose reaction vessels are removed from the process carousel by operation of the transfer station which includes a means for removing the disposable reaction vessel from the system. According to such an analytical System device, a system scheduler generates and optimizes the workload for the system's mechanical resources from all the tests that are put to run in the system. The main goal of the scheduler is to keep the system's resources from being idle while there are still tests that need to be processed by the system. By keeping each of the resources busy, the amount of time required by the device to run the tests also decreases.

A high-level view of the scheduling process can be divided into two stages: (1) ensuring the appropriate scheduling of each activity in a test before the test is cemented, and (2) an attempt to perform each test activity before its originally scheduled execution time in order to minimize idle time of resources and increase test throughput in the system. To enable the scheduling of a test before it is executed in the system, each test assay protocol contains several timing parameters that are used in the setup process. Each activity in the test contains time values that are used by the scheduler to determine what resources the activity requires and the length of time those resources will be needed. Also, each activity in the test can be tied to other activities by incubation periods. These incubation periods, determined by the chemistry of the assay, help the scheduler determine the amount of time that must elapse between the execution of two activities. Each incubation period in the assay protocol provides the minimum and maximum time that must elapse between the performance of each activity. These boundaries are referred to in the planning process as the incubation window for the activities.

When operating such an analytical system instrument, the operator selects the order in which these tests are prepared for run on the instrument by selecting the positioning of the samples on the instrument. The sample positioned closest to the pipette station is the first sample prepared to run on the instrument. To To protect against evaporation, a test will not be prepared until the scheduler ensures that all resources used by the test activities will be available at the required times specified in the assay protocol for the test. Preparation of a particular test will be postponed whenever an activity on another test already on the instrument uses a resource that is scheduled at a time when it is needed for an activity on that test. The sample preparation area of the instrument will remain idle until the test can be scheduled without conflicting with tests already on the instrument. If proper scheduling of the test can be achieved, the test will be prepared and transferred to the processing area.

The second step in the scheduling process is to optimize the utilization for each system resource to minimize both the idle time of the resource and the time required to complete the utilization of the resource; once the tests are transferred to the processing area, the scheduler optimizes the existing schedule for each resource. At predetermined intervals, the scheduler examines the next work interval for each resource; if there is any idle time in that interval, the scheduler attempts to minimize the idle time by reordering the utilization of the resource to eliminate the idle time while ensuring that activities remain within their allowed incubation windows. Once optimization of these intervals is complete, that portion of the utilization is performed at the resource's designated times. The scheduler continues to prepare samples as long as there are samples on the device that have tests to be tested. Optimization of the workload of the resources continues until all tests transferred to the system have completed processing. The analytical instrumentation system described herein allows special priority handling of special samples that the user has designated as priority samples (i.e. samples to be processed immediately) A priority sample is a sample that must be processed by the instrument in the shortest possible time. Special handling of priority samples takes place both in the front sample inlet area and in the processing area of the instrument.

When a priority procedure is performed, the operator selects the order in which the tests are prepared for run on the instrument by selecting the placement of the samples on the instrument. The sample closest to the pipette station is the first sample prepared to run through the instrument. This pattern of sample preparation is interrupted whenever the user places a priority test on the instrument. Whenever a priority test is required, the system will complete test preparation on the current sample and then go directly to the priority sample to prepare all of its tests. To protect against evaporation, sample preparation for a test will not start until proper scheduling of test activities is ensured in the processing area. The system scheduling algorithm is also modified for priority processing. The scheduling algorithm used for normal testing attempts to maximize the number of tests processed on the instrument each hour. This is done by allowing sufficient time between testing activities to enable additional testing activities to be performed in those time gaps. The scheduling approach used for priority testing attempts to handle that one test in the shortest amount of time possible. Each activity of a priority test is scheduled to run at the earliest possible time, as determined in the test's assay definition. When all activities of a test are guaranteed proper scheduling on the instrument, the test's sample preparation will start. After all tests on the priority sample are prepared, the system will return to the sample it was working on before servicing the priority sample.

Priority tests are subject to special consideration in processing area when there is an idle time in a resource's workload. At predetermined intervals, the scheduler examines the next work interval allocated to each resource in the system's processing area. If there is no idle time during that interval, the scheduler attempts to minimize it by reordering the resource's workload. Test activities scheduled for that resource that can be performed earlier than currently scheduled - as determined by their assay protocols - are moved forward to fill the idle time. Priority test activities are the first candidates to be moved forward in processing, further reducing the time required to process the priority test in the instrument. The priority system test handling algorithms have been shown to allow the priority tests to be processed in the shortest amount of time without having a negative impact on the instrument's overall throughput of tests per hour.

The analytical cuvette of the present invention can be used with various analytical instruments described herein and other instruments known in the art that employ various detection systems including, but not limited to, spectrophotometric absorbance assays such as endpoint reaction analysis and rate of reaction analysis, turbidity assays, nephelometric assays, radiant energy attenuation assays (such as those described in U.S. Patent No. 4,496,293 and U.S. Patent No. 4,743,561, the contents of which are incorporated herein by reference), ion capture assays, colorimetric assays, fluorometric assays, electrochemical detection systems, potentiometric detection systems, amperometric detection systems, and immunoassays. Immunoassays include, but are not intended to be limited to, heterogeneous immunoassays such as competitive immunoassays, sandwich immunoassays, immunometric immunoassays and the like, wherein the amount of detectable moiety used therein is measured and related to the amount of analytes present in the test sample.

In a spectrophotometric assay such as those performed on the Abbott Clinical Spectrum Analyzer and the Abbott Clinical Spectrum Analyzer Series II (Abbott Laboratories, Abbott Park, IL, USA), the interaction in an assay solution between the analyte to be determined and a reagent system specific to the analyte generally produces a detectable change in the transmittance properties of the assay solution. The change in transmittance properties refers to the fraction of light absorbed and scattered by an assay solution within a specific wavelength band when a light beam of known intensity is passed through the assay solution. The change in transmittance properties of an assay solution is measured by passing monochromatic light having a known intensity through the assay solution and determining the ratio of the intensity of the transmitted or scattered light with respect to the intensity of the incident light. Almost all analytes either absorb the energy from a specific wavelength or interact with a specific reagent system in an assay solution to produce a detectable change in the transmittance properties of the assay solution characteristics, which has led to the development of the numerous specific spectrophotometric assays. The spectrophotometric assays that are based on measuring the change in the transmittance properties of an assay solution as a measure of an analyte in the assay solution include, for example, assays in which there is a color change of the assay when there is a change in the turbidity of the assay solution - i.e., turbidity assays or nephelometric assays.

In a colorimetric assay, the change in the transmittance properties of an assay solution is generally referred to as the absorbance of the assay solution and depends on the color change of the assay solution due to the interaction of the analyte to be determined and the reagent system specific to the analyte. The absorbance of the assay solution is related to the concentration of the analyte in the assay solution. A colorimetric assay uses a color reagent system capable of interacting with the specific analyte of interest in an assay solution to produce a detectable change in the transmittance properties, specifically the color, of the assay solution. Numerous color reagent systems useful for the determination of the specific analyte have been developed and are commercially available.

The principle of turbidity assays is to determine the fraction of light scattered or blocked by suspended particles as the light passes through an assay solution. In a turbidity assay, the analyte of interest interacts with a reagent system specific to the analyte to form a suspension of the particles in the assay solution. When a beam of light having a known intensity is sent through an assay solution, the particle suspension formed by the interaction of the analyte-reagent system blocks or scatters the incident light, thereby reducing the intensity of light passed through the assay solution. The change in transmittance properties in a turbidity assay relates to the decrease in the intensity of light transmitted by an assay solution, is related to the fraction of incident light that is scattered or blocked by the suspension of particles, and depends on the number of particles present and the cross-sectional area of such particles.

A nephelometric assay is similar to a turbidity assay in that the analyte of interest interacts with a reagent system specific to the ligand to form a suspension of the particles in the assay solution. In a nephelometric sample, the change in the transmittance properties of the assay solution also affects the proportion of incident light scattered or blocked by the suspension of particles; unlike a turbidity sample, in which the intensity of light transmitted through the assay solution is measured, the scattered or blocked light is measured at an angle with respect to the incidence of light on the assay solution. Therefore, in a nephelometric assay the change in the transmittance properties the difference in the intensities of light incident on the assay solution and the light scattered at an angle with respect to the incident light. Turbidity and nephelometric assays are used in the analysis of blood, urine, spinal fluid and the like for the determination of an analyte such as proteins, where there is no comparable colorimetric sample due to the lack of an effective color reagent system. Yoe and Klimman, "Photoelectric Chemical Analysis", Vol. II; Nephelometry, Wiley & Sons, Inc., New York, 1929, describe various nephelometric assays. Various reagents and reagent systems that can be used to perform spectrophotometric assays on the automated analytical systems described herein include, but are not intended to be limited to, such systems for the simultaneous determination of glucose and urea as described, for example, in U.S. Patent No. 5,037,738, the contents of which are incorporated herein by reference. The simultaneous determination of calcium and phosphorus, the simultaneous determination of cholesterol and triglycerides, the determination of isoenzymes, the determination of blood ammonia levels, and the like, can be performed using the analytical cuvette of the present invention.

Typically, in a fluorometric assay, an analyte in an assay solution is chemically or immunologically converted to a fluorescent complex or conjugate, thereby producing a detectable change in the fluorescent properties of the assay solution. The change in the fluorescent properties of the assay solution is measured by exciting the fluorescent complex or conjugate properties produced with monochromatic light of a wavelength within the excitation waveband of the fluorescent agent and by measuring the intensity of the emitted light at a wavelength within the emission wavelength band of the fluorescent agent. The fluorescence intensity of the emitted light is dependent on the concentration of the analyte. However, the The intensity of the fluorescence emitted by the assay solution may be inhibited if the ligand to be determined forms a complex group with non-fluorescent interferents such as protein or phosphates present in the sample, or if the sample containing the ligand to be determined is sufficiently colored to act as a filter and thereby reduce the intensity of the fluorescence emitted. It is generally recognized that in order to maximize the sensitivity and specificity of a fluorometric assay, these inhibiting factors, if present, must be overcome either by removing the non-fluorescent interferents or color-producing material prior to analysis or by compensating for the absence of such factors by adding an internal standard to the second aliquot of the sample and performing the entire assay procedure using the aliquot containing the internal standard.

In general, homogeneous and heterogeneous immunoassays depend on the ability of a first member of a binding pair to specifically bind to a second member of a binding pair, wherein a conjugate comprising one of these binding pair members labeled with a detectable moiety is used to determine the extent of such binding. For example, when such binding pair members are an analyte and an antibody to such analyte, the degree of binding is determined by the amount of detectable moiety present in the conjugate that has either participated or not participated in a binding reaction with the analyte, wherein the amount of detectable moiety detected and measured can be correlated with the amount of analyte present in the test sample.

The homogeneous immunoassays are usually performed in a competitive immunoassay format, which involves a competition between an analyte from a test sample and an indicator for a limited number of the receptor binding sites on an antibody to the analyte. The indicator comprises the analyte or an analogue thereof labelled with a detectable moiety, wherein the concentration of the analyte in the test sample determines the amount of indicator that will specifically bind to the antibody. The amount of indicator-antibody conjugate produced by such binding can be measured quantitatively and is inversely proportional to the amount of analyte present in the test sample. Fluorescence polarization methods for providing such a determination, such as in the fluorescence polarization immunoassays described herein, are based on a principle that a fluorescently labeled compound, when excited by linearly polarized light, will emit fluorescence having a degree of polarization that is inverse to its rotational speed. When a molecule, such as an indicator-antibody conjugate having a fluorescent label, is excited with a linearly polarized fluorescent molecule, it is forced to rotate in the period of time when light is absorbed and emitted. When a "free" indicator molecule (i.e., not bound to an antibody) is excited by linearly polarized light, its rotation is much faster than the corresponding indicator-antibody conjugate, and the molecules are more randomly aligned; therefore, the emitted light is polarized. Accordingly, when plane-polarized light is passed through a solution containing the aforementioned reagents, a fluorescence polarization response is detected and correlated with the amount of analyte present in the test sample. Various fluorescent compounds that can be used to perform fluorescence polarization assays include, but are not intended to be limited to, aminofluoresceins, such as those described in U.S. Patent No. 4,510,251 and U.S. Patent No. 4,614,823, incorporated herein by reference; Triazinylaminofluoresceins, for example, as described in U.S. Patent No. 4,420,568 and U.S. Patent No. 4,593,089, incorporated herein by reference; carboxyfluoresceins, for example, as described in U.S. Patent No. 4,668,640, incorporated herein by reference; and the like.

Heterogeneous immunoassays typically involve a labeled reagent or indicator comprising an analyte, an analog of the analyte, or an antibody thereto labeled with a detectable moiety to form a free species and a bound species. In order to correlate the amount of indicator in such a species with respect to the amount of analyte present in the test sample, the free species must first be separated from the bound species, which can be accomplished according to methods known in the art that utilize solid phase materials for the direct immobilization of one of the binding participants in the binding reaction, such as an antibody, analyte, or analog of the analyte, wherein one of the binding participants is immobilized to a solid phase material such as a test tube, beads, particles, microparticles, or the matrix of a fibrous material, and the like, according to methods known in the art.

Heterogeneous immunoassays can be performed in a competitive immunoassay format, as described above, wherein, for example, the antibody can be immobilized to a solid phase material, whereby upon separation the amount of indicator bound to such solid phase material can be detected and correlated with the amount of analyte present in the test sample. Another form of heterogeneous immunoassay using a solid phase material is referred to as a sandwich immunoassay, which involves contacting a test sample, for example containing an antigen, with a protein such as an antibody or other substance capable of binding the antigen, and which is immobilized to a solid phase material. The solid phase material is usually treated with a second antigen or antibody which has been labeled with a detectable moiety. The second antigen or antibody is then bound to the corresponding antigen or antibody on the solid phase material, and following one or more washing steps to remove any unbound material, an indicator material - such as a chromogen substance - reacts with the detectable moiety (e.g., where the detectable moiety is an enzyme, a substrate for such enzyme is added) to produce a color change. The color change is then detected and correlated with the amount of antigen or antibody present in the test sample. For example, the assay cuvette of the present invention can be used in a heterogeneous immunoassay which can be performed by the automated analytical system described herein in either a competitive or sandwich immunoassay format in a microparticle capture enzyme immunoassay such as that described in Clinical Chemistry, Vol. 34, No. 9, pp. 1726-1732 (1988) which uses microparticles as the solid phase material. In addition, the use of sucrose in the microparticle diluent has been found to achieve a neutral density of the microparticles. The methodology involves determining the optimal sucrose concentration that will eliminate sedimentation of the microparticles. The sucrose concentration required to achieve neutral density is assay specific and microparticle lot specific. The principle involves dissolving the sucrose in the solution to increase the density of the diluent. If the density of the diluent and the microparticles are equivalent, the microparticles will be in a suspended state. Density neutralization can also be achieved using other materials such as metrizamide and/or metrizoic acid.

The separation of bound and free species is achieved by trapping the microparticles on a glass fiber matrix of a MEIA cartridge, a process that relies on the high affinity of the glass fibers for the microparticles, whereby the microparticles adhere irreversibly to the surface of the fibers and the non-specifically bound materials can be effectively removed by washing the matrix. The matrix provides of the assay protocol as described herein, also provides a precisely positioned mechanical support for the microparticles.

When a sandwich immunoassay is performed, the microparticles coated with the antibody to the analyte in the test sample are incubated with the test sample containing the analyte of interest to form a capture complex with the analyte from the test sample. A conjugate comprising antibody to the analyte labeled with a detectable moiety, preferably an enzyme, is then incubated with the capture complex to form a second sandwich complex. When a competitive immunoassay is performed, the microparticles coated with the antibody to the analyte in the test sample are incubated with the test sample containing the analyte of interest and a conjugate comprising the analyte or its analog labeled with a detectable moiety, preferably an enzyme. Removal of the unbound conjugate is accomplished with the glass fiber matrix of the MEIA cartridge, and when the detectable moiety is an enzyme, a substrate capable of providing a detectable signal is added for the enzyme, and the signal thereby provided is measured and correlated to the analyte moiety present in the test sample. Preferably, the enzyme-substrate system utilized by the competitive and sandwich MEIA formats is alkaline phosphatase and 4-methylumbelliferyl phosphate (MUP), although other enzyme-substrate systems known in the art may be used as well.

The MEIA cartridge includes a reaction vessel for retaining and immobilizing the microparticle-analyte complex. The reaction vessel has an inlet port and means for holding a sample quantity and assay reaction mixtures positioned over a fibrous matrix that retains and immobilizes the microparticle-analyte complexes as described above. The fibrous matrix is comprised of fibers having a mean spatial separation that is greater than the mean diameter of the microparticles. The mean fiber spatial separation is preferably greater than 10 microns. The reaction vessel further comprises an absorbent material positioned beneath the fibrous matrix to enhance the flow of sample and assay reaction mixture through the fibrous matrix.

Preferably, the absorbent material is a fibrous material, the fibers of which lie predominantly in a plane vertical to the lower surface of the fibrous matrix. The absorbent material is in fluid communication with the fibrous matrix. Generally, the absorbent material is in physical contact with the lower surface of the fibrous matrix. The interior of the reaction vessel is therefore generally sized or contains a positioning means to maintain fluid communication between the absorbent material and the fibrous matrix. Preferably, a mandrel located on the bottom of the reaction vessel can be used to bring the absorbent material into contact with the lower surface of the fibrous material. In addition, it is preferred to vent the gases displaced in the absorbent material by the liquids absorbed therein to the atmosphere during the performance of an immunoassay. According to the immunoassay procedures described above, analyte standard solutions of known concentrations covering the clinical concentration range are usually prepared and analyzed in the same way that the test sample is to be analyzed. This blank assay provides a series of signal measurements corresponding to the known concentrations from which a standard curve is drawn. The optical signal corresponding to the unknown sample is correlated to a concentration value using interpretation from the blank or standard curve.

The automated analytical procedures for performing analysis for a plurality of test samples according to the analytical instrumentation system described herein are accomplished by introducing reagent packs, test sample containers and reaction vessels onto the concentric carousels of a main carousel. The test sample container may be a test tube, a cuvette, a vacuum container (vacutainer) and the like for holding a test sample. The reagent packs and the test sample containers are identified and each aligned with a reaction vessel for transfer and for sealing the reaction vessel by transferring the test sample and specific reagents from the reagent packs to prepare for a predetermined test. The reaction vessel containing the test sample and one or more reagents is transferred to a processing carousel wherein the controlled environmental conditions for incubation exist once the sample has been properly mixed with various reagents to form a reaction mixture. When all assay processing steps have been completed, the reaction mixture is identified and transferred to, for example, either a fluorescence polarization immunoassay reader or a microparticle enzyme immunoassay cartridge positioned on a separate cartridge wheel or carousel for further preparation prior to the reading process. The processed test samples are read and the readings are calculated and/or printed with the recorded resulting data.

The automated analytical immunoassay system operation is accomplished through the use of a self-contained, fully automated, continuous random access device comprising a main carousel assembly consisting of the reagent pack carousel, a reaction vessel carousel, and a test sample container carousel which can be concentrically and independently rotated. The main carousel assembly is provided with a cantilever arm operated transfer pipette to automatically transfer and pack test samples and reagents into the reaction vessel following a predetermined test schedule. The main carousel assembly is provided with bar code readers for reagent packs and test sample containers and has the capability to align the reagent pack carousel and the test sample container carousel and a reaction vessel for the pipette transfer operations. Once the assay to be performed is planned, the reaction vessel carousel, the reagent pack carousel and the test sample container carousel are rotated until it is determined that the reaction vessel, a Reagent pack and a test sample container are located at the transfer pipette access point. The transfer pipette then transfers the test sample from the test sample container and, depending on the assay being performed, the reagents from the reagent pack are transferred to the reaction vessel. The reaction vessel carousel is then rotated to a transfer station point which brings the reaction vessel into contact with a transfer mechanism and draws the reaction vessel into the transfer station. The reaction vessel is then loaded onto the process carousel by the transfer mechanism.

When a fluorescence polarization immunoassay (FPIA) is performed with the automated analytical system, various pipetting activities are performed by a second transfer pipette device serving the process carousel, and the process carousel is then rotated so that the reaction vessel - when properly pipetted with, for example, FPIA reagents - is located at the reading station of the FPIA processing stations, and upon reading, the FPIA determination is performed on the reaction vessel. The process carousel is then rotated so that the reading reaction vessel is located at the transfer station. The reaction vessel is in turn brought into contact with and transferred from the transfer station. The transfer station is rotated and pushes the reaction vessel into a dispensing container opening.

For a microparticle enzyme immunoassay (MEIA) performed with the automated analytical system described herein, after the various pipetting activities for the MEIA, which can be completed on the main carousel assembly, the reaction vessel is transferred to the process carousel as described in the FPIA procedure. Pipetting can also be accomplished in the process carousel or in the two carousels combined. To complete the MEIA, the reaction mixture is transferred from the reaction vessel to a matrix of a MEIA cartridge on a cartridge carousel using the second transfer pipette. The matrix is mixed with a buffer and a substrate such as a MUP (previously defined) or other suitable substrate known in the art. The cartridge carousel is then rotated so that the MEIA cartridge is positioned on a MEIA processing setup and the MEIA determination is performed. The MEIA reaction vessel is ejected into the waste container as described for the FPIA reaction vessel. The MEIA cartridge is ejected into a waste container by an ejector at an appropriate ejection station independent of the cartridge wheel.

Preferably, as described above, two different analytical technologies, FPIA and MEIA, are included in the automated analytical system described herein with which the analytical cuvette of the present invention can be used. However, more than two different analytical technologies can be included in the analytical system. These methods are complementary and share a set of equipment and process steps, with the FPIA generally being the selection method for low molecular weight analytes and the MEIA being that for molecules such as protein hormones, antibodies or low molecular weight analytes that require higher sensitivity. The two technologies share system components that include the operator panel, pipetting boom assemblies, fluid systems, air and liquid reagent heaters, printers, a bar code reader, and stepper motors. Such a combination of system components allows for a compact device despite the dual FPIA and MEIA capability.

The FPIA optical systems (for example, as described in U.S. Patent No. 4,269,511, the contents of which are incorporated herein by reference) may employ a polarizing filter that is an electrically switched liquid crystal, which is compact in size and avoids complex and potentially unreliable moving parts. When performing FPIA assays using the automated analytical system described herein, the FPIA reagent packs will typically include an indicator comprising the analyte or an analog thereof that is coupled to a detectable moiety, an antibody specific for the analyte, and a sample pretreatment reagent. In a preferred FPIA format, the particular analyte competes with the indicator for a limited number of binding sites on the antibodies specific for the portion or portions of the analyte and the indicator. The detectable moiety component of the indicator is preferably a fluorescent moiety selected from the group consisting of fluoresceins, aminofluoresceins, carboxyfluoresceins, fluoresceinamines, and the like, more preferably carboxymethyl-aminomethyl-fluorescein, carboxethylaminomethyl-carboxyfluorescein, 6-carboxyfluorescein, 5-carboxyfluorescein, succinylanimomethyl-fluorescein, thiourea-aminofluorescein, methoxytrianolylaminofluorescein, aminofluorescein, and the like.

MEIA results can be determined by quantifying the rate of fluorescence developed when the fluorophore substrate is converted by the action of an enzyme-labeled conjugate. For example, when performing either competitive MEIA or sandwich MEIA, the alkaline phosphatase specifically bound to the microparticles is detected by adding the fluorophore substrate MUP to the matrix. The alkaline phosphatase catalyzes the hydrolysis of the MUP to an inorganic phosphate and fluorescent 4-methylumbelliferone (4-MU). The liberated 4-mu is detected by the front surface fluorometer of the optical MEIA setup, which is designed to detect the fluorescence of low concentrations of 4-MU without interference from the fluorescence of the 4-MUP at a wavelength of 367 nm. A system of lenses and optical filters focuses filtered light (wavelength = 365 nm) from a mercury arc lamp onto the surface of the matrix and focuses emitted fluorescence from the 4-MU (wavelength = 448 nm) onto a photomultiplier tube. Like the FPIA optical setup, the MEIA optical system is compact and has no moving parts. About five percent of the excitation light is captured by a photodiode, which Standardization of the fluorescence data and generation of a control signal used by the lamp power supply to maintain the intensity of the excitation light within five percent over the useful life of the lamp. The MEIA postprocessor uses linear regression analysis to convert the data from the multiple consecutive determinations of 4-MU fluorescence to a rate proportional to the concentration of alkaline phosphatase conjugate specifically bound to the microparticles.

MEIA formats can be run with a multi-position MEIA staging carousel and a process carousel, as well as with a reagent pack containing a microparticle reagent, an alkaline phosphatase conjugate, and in some cases a dilute buffer specific to the sample being run. Since the microparticles do not tend to separate from the suspension during the assay run, they can be easily pipetted. The effective surface area of the polystyrene latex microparticles is several folds larger than the polystyrene beads traditionally used in commercial immunoassays (e.g., one-quarter inch beads). Due to this large surface area and the very small diffusion distance between the analyte and the capture molecules on the surface of the microparticles, the capture phase used in many performed MEIA procedures will reach equilibrium within several minutes, allowing a whole carousel of test samples to be run in a short time frame.

Unlike an FPIA, heterogeneous immunoassays such as a MEIA require a separation step as described above. In particular, after incubation of the microparticles with a test sample, the microparticles are separated from the reaction mixture by transferring them to the matrix contained in the MEIA cartridge, as described above. The matrix provides the microparticles with a precisely positioned mechanical support during the subsequent optical reading phase of the sample. This precisely positioned support, ie the carousel, is fitted with the makeshift carousel at a predetermined distance from the reader by means of a clamping device.

Referring to the drawings, Figures 1 and 2 show isometric views of an automated analytical immunoassay system device with which the assay cuvette of the present invention is particularly useful. It should be understood that the automated analytical immunoassay system described herein is set forth only in connection with the components of primary interest with reference to the assay cuvette of the present invention. The drawings do not illustrate all of the mechanical and electrical elements for operating and controlling various components of the system, wherein each of these omitted elements may take various known forms that can be readily realized by one of ordinary skill in the art having knowledge of the information provided herein regarding the mode of operation of the system and the various components and associated methods used to treat samples and determine analytical results.

The system device as it appears in Fig. 1 shows the system device as used by the technician, with Fig. 2 being an isometric view of the frame and housing with some component parts removed. The system device described herein is generally designated by the reference numeral 2 in Fig. 1. The system device 2 has an exposed front end carousel 4 operated by a first transfer pipetting mechanism 6 to kit planned tests along with the samples into a reaction vessel. The system provides a computer display 8 and a computer keyboard 10 along with access panels 12 to access storage and waste compartments. The system device 2 is provided with casters 14 for movement of the system device within a laboratory complex as required. The freedom of movement of the system device by means of casters 14 is permitted since the system is self-contained for power requirements. is completed.

In Fig. 2, the housing frame 16 of the system device 2 is shown with substantially all functional components of the system device removed. A controlled environment area 18 is a closed unit during operation, with light protection and tight control of air flow and temperature, in contrast to the open front end carousel 4. The front end carousel 4 communicates with the controlled environment area 18 by means of a transfer port 20. The front end carousel 4 is mounted on an aluminum base plate which rests on a support platform 22 and the first transfer pipette mechanism is attached to the means 24.

The cross-sectional plan view of Fig. 3 shows the functional component system device in some detail with the relative positioning of the system device to further illustrate the process flow of the system device. For example, sample cups 26 may be attached to a sample cup carousel 28 which is concentrically fitted in the front end carousel 4 together with the reagent pack carousel 32 and the reaction vessel carousel 36. The reagent pack carousel 32 is concentrically fitted between the sample cup carousel 28 and the reaction vessel carousel 36. The reagent pack carousel carries reagent packs 30 and the reaction vessel carousel 36 carries reaction vessels 34. The front end carousel 4 has an operable bar code reader 38 to automatically identify the reagent pack carousel 32 and the sample carousel 28. A wash cup 40 is provided for the first transfer pipette mechanism 6 to wash various samples and reagents as required between transfers. The first transfer pipette mechanism 6 is used in kitting the various liquid reagent pack materials and sample into a reaction vessel 34. The reagents and sample are appropriately kitted by the first transfer pipette mechanism 6 including a pumping means. The various carousels are rotated and aligned to kit at the pipette station. The The cemented reaction vessel 34 is positioned by the reaction vessel carousel 36 for transfer to the transfer station 42. The reaction vessel 34 is transferred to the transfer station 42 by a transfer means, wherein the transfer station 42 is then rotated to move the reaction vessel into the process carousel 46. As shown, the process carousel is driven by a stepper motor 48 and served by a second transfer pipette mechanism 50. Both the FPIA and MEIA processes share the system equipment up to and including the process carousel 46. The process carousel 48 includes an FPIA processor 52 and an FPIA processing lamp 54 to immediately read the FPIA analysis of the cemented, pipetted and appropriately reacted reagent sample from the reaction vessel 34. The controlled environment area 18, which includes the transfer station 42 and the process carousel 46, provides for FPIA processing with air circulation under temperature control by a housing air circulation fan 56. A wash cup 58 is provided for the second transfer pipette mechanism 50. The second transfer pipette 50 is used to add reagents (pipetting) under incubation conditions and timing conditions to the sample in the FPIA test planning reaction vessel 34 for FPIA processing. MEIA processing may also use the second transfer pipette 50 to add reagents to the sample before the reaction mixture is delivered to the MEIA cartridges 68 mounted on the cartridge wheel carousel 64. The transfer of the reagent mixed sample to the MEIA cartridge 68 is accomplished by the operation of the second transfer pipette 50. A motor 60 drives the cartridge wheel 64. The cartridge wheel 64 is provided with the MEIA cartridges 68 by the operation of a cartridge hopper 66 which automatically guides and positions the MEIA cartridges 68 over the cartridge wheel 64. The process area includes the second transfer pipette mechanism 50 and a heater/pump 44. The cartridge wheel carousel 64 is further provided by a MEIA buffer heater and a manifold 70, a MUP heater and manifold probe 72, and a MEIA reader 74. The MEIA cartridges 68 are removed from the cartridge wheel 64 by a cartridge ejector 62 after the MEIA reading operation is completed.

It should be understood that the use of the first transfer pipette mechanism 6 and the second transfer pipette mechanism 50 as described herein provides a safety mechanism to ensure that test samples and reagents are pipetted, thereby preventing false negative results in the event that there are incorrect amounts of the respective sample and reagents for a particular assay.

Approaching the operable elements of the system device in more detail, Figure 4 provides an isolated front elevation view and partial cross section of the elements of the front end carousel 4. Figures 4A and 4B illustrate a reagent pack having a cover means 31 that is opened and closed by rotating along axis 37. A notched return drive arm 35 is used to open and close the cover means 31 by contact with the cover contact surface 33.

Figure 5 provides an isolated top view and partial cross section of the elements of the drive and guide system of the main carousel 4 with the various carousels removed. In Figure 5, a sample cup carousel stepper motor 76 is shown attached with a mounting spring 78. The reagent pack carousel motor 80 is also shown with a mounting spring 82. The reaction vessel carousel motor 84 and mounting spring 86 are positioned on the outside of the two inner carousels - i.e., the sample cup carousel 28 and the reagent pack carousel 32. Roller guides 88 are provided for the sample cup carousel 28 and a tension spring 90. The reagent pack carousel is provided with roller guides 92 and a tension means 94. The reaction vessel roller guides 96 are also provided with spring elements 98, the task of the guide and these various spring elements 98 being to to obtain very finite tracking of the concentric carousels when they are moved by the individual stepper motors.

The front end carousel 4 including the three front end carousels, the sample cup carousel 28, the reagent pack carousel 32 and the reaction vessel carousel 36, may, for example, include the following capabilities. The sample cup carousel 28 may hold 60 blood collection tubes such as vacuum blood collection tubes (vacutainer blood collection tubes) or 90 sample cups which may be injection molded as one piece and provided with freestanding base supports. The freestanding base supports are suitable for handling and pipetting of the samples into the sample cups by a technician. The reagent pack carousel 32 provides 20 different reagent packs 30. The reaction vessel carousel 36 provides 90 reaction vessels 34.

The process carousel 46 as shown in Figure 6 is shown in an isolated cross-sectional side view. One reaction vessel 34 is in a resting or non-operating position and a second reaction vessel 34 is in a location for the FPIA reading operation. The process carousel 46 is capable of bi-directional movement to temporally move the various reaction vessels 34 to and from the carousel for pipetting device operation, reading or transfer. Up to about 36 or more reaction vessels 34 can be processed at one time on the process carousel 46 depending on the diameter and dimensions of the reaction vessels 34.

The first transfer pipette mechanism 6 of Fig. 7 includes a transfer pipette Z-axis motor 102 that moves the probe arm 104, probe 106, and probe end 108 in a vertical direction, while the transfer pipette R-axis motor 100 operates the probe arm 104, probe adjustment means 106, and probe end 108 in a horizontal motion. The first transfer pipette mechanism 6, sometimes referred to as a "sample probe arm mechanism," moves the probe between the sample cup 26, the reagent pack 30, the reaction vessel 34 and the wash cup 40. The wash cup 40 is used to wash the inner and outer surface of the first transfer pipette mechanism 6 probe. The drive of the first transfer pipette mechanism is a rack and pinion drive means along the Z and R axes by two stepper motor drive means. A brake is provided to hold the Z axis position when the power is turned off, thereby preventing damage to the system device. For example, the first transfer pipette mechanism may be constructed to have a Z axis travel of about 3 inches and an R axis travel of about 11-1/2 inches.

The first transfer pipette mechanism 6 and the second transfer pipette mechanism 50 are closely related in general function and system device design, with the change in travel and size being the only significant changes. Both units include a probe arm circuit 110 as shown in the schematic side view of Figure 8. The schematic view illustrates the R-axis motor 100 and the Z-axis motor 102 in relation to an upper PCB 112 and an R-axis home point sensor 114. A lower PCB 116 is shown in relation to the Z-axis home point sensor 118, with a coil cable 120 connecting the various elements.

Various elements of a syringe 122 which provides automatic bubble flushing and fluids to the various pipetting mechanisms are provided in numerous views in Figs. 9, 9A and 9B. The ability of diagnostic measurement methods to accurately perform an assay depends critically on the precision and accuracy with which the syringes, i.e. pipetting, can aspirate and dispense the reagents and samples. The precision and accuracy of a syringe is greatly degraded by the presence of small air bubbles in the syringe. Unfortunately, bubbles are always present and are difficult to remove or avoid. The syringe 122 overcomes these difficulties by completely flushing the bubbles from the fluid system. The syringe 122 is constructed such that a piston 124 reciprocates through a seat 126 and within a tightly fitting bore 128. The piston 124 has a piston end 132 which approximates the geometry of the closed bore end 130. Two ports to the bore are 180º apart and near the seat and consist of a fluid inlet port 134 and a fluid outlet port 136. An annulus 138 exists between the piston 124 and the bore 128. Pressurized line diluent is introduced into the fluid inlet port 134. The fluid flows around both sides of the piston 124 into the annulus 138 and then into the fluid outlet port 136. This cross flow flushes bubbles from the area near the seal. As crossflow occurs, piston 124 is reciprocated within bore 128. This reciprocating motion causes high fluid flow velocities in the annulus 138 between piston 124 and bore 128. The high flow velocity dislodges any bubbles that may be stuck to piston 124 or the bore wall. The inward stroke of the piston pushes these bubbles across the crossflow region where they are expelled from the syringe. Piston end 132 and bore end 130 have similar circular shapes. As piston 124 reaches its full inward extension, it comes very close to bore end 130. Any bubbles that may be stuck to bore end 130 are broken down and dislodged. Similarly, when the piston 124 reaches its full outward extension, its end abuts against the seal 126. The process of reciprocating the piston during cross flow can be performed automatically each time by the system device.

Once the fluid leaves the syringe fluid exit port 136, it must travel through a tube fitting, through the length of the tube, through another tube fitting, into a probe 106, and out the probe end 108. The aspiration and dispensing of reagents actually occurs at the probe end 108. Any bubbles trapped between the syringe and the probe end will also degrade performance, so there is no room for the bubbles being flushed out of the syringe to It is therefore necessary to use zero dead volume pipe fittings on the pipe between the syringe and the probe.

Reaction vessel 34 is discussed in detail with respect to both MEIA planning and FPIA planning in Figures 10, 10A, 10B, and 10C. Figures 10 and 10A show FPIA kit use. Reaction vessel 34 includes an assay cuvette 140 prepared according to the method of the present invention as described above. The reaction vessel is shown in both plan view (Figure 10) and side view (Figure 10A). S-reagent antiserum is deposited in recessed container 142, while T-reagent indicator is deposited in recessed container 144, with P-reagent popper stored recessed in container 146. The recessed containers 150 and 152 may serve to provide a variety of reagents, buffers and/or diluents to the device. The sample is stored in recessed container 148 and the pre-diluent is stored in recessed container 154. The use of the transfer pipetting device in storing the required reagents in a reaction vessel along with the sample is called kitting. The depositing of the various required reagents and the like in a single reaction vessel along with a sample to be analyzed is called pipetting.

The MEIA reaction vessel, as shown in the top and side views of Figures 10B and 100, respectively, contains the prediluent in recessed container 156; microparticles stored in recessed container 158; conjugate directly in reaction container 166; assay diluent in recessed container 162; and sample in recessed container 164. The buffer container is numbered 168 and the prediluent container is numbered 170. Once kitting is complete, many of the subsequent FPIA and MEIA pipetting steps can be performed in either the main carousel or the process carousel using the pipetting mechanisms of both carousels. This is possible because the kitted Reaction vessel, once cemented, is immediately transferred to the transfer station and thus to the process carousel, which is located in a temperature controlled environment.

The transfer station 42 plays a key role in the apparatus and process function. In Fig. 11, a side cross-sectional view of the transfer element of the transfer station 42 is shown engaging the reaction vessel 34 by means of a reaction vessel transfer boom 172. The transfer arm 173 projects outwardly between the reaction vessel elements of the reaction vessel carousel 36 and engages the reaction vessel transfer boom 172 by the rotation of the transfer station 42. By means of a transfer arm drive shaft gear 174, the transfer arm 173 of the rack gear 176 moves the transfer a = 173 out of and into relation with the transfer station 42. The transfer station 42 has a rotation axis 178. In Fig. 11A, a reaction vessel is shown in phantom as it would be mounted on the front end carousel 4 with the reaction vessel carousel 36 engaging the transfer arm 173 by means of the reaction vessel transfer boom 172. The reaction vessel 34 in Fig. 11 is illustrated at the transfer station with the reaction transfer station 42 moving the reaction vessel 34 between the front end carousel 4 and the process carousel 46. The transfer station 42 moves the discarded reaction vessel 34 from the process carousel 46 to the waste ejection station (not shown). The transfer station 42 is operated by a stepper motor drive and supported by precision linear ball bearings and rotary ball bearing axes.

For example, the process carousel 46 carries 36 reaction vessels 34 and has a carousel diameter of approximately 12.5 inches. The process carousel 46 moves the reaction vessel 34 between the transfer station 42, the second transfer pipettor mechanism 50, the pipetting point and the FPIA reader processing. The process carousel 46 is driven by a stepper motor and is supported by three wheels which are used for height control and control of any radial movement caused by incorrectly shaped carousel elements.

The second transfer pipette mechanism 50 moves the pipette probe between the containers in the reaction vessel 34 on the process carousel 46 to the MEIA cartridge 68 on the auxiliary carousel 64 and to the wash cup 58. A rack and pinion drive using two-axis stepper motor drives achieves precision drive on the R and Z axes. For example, the travel on the Z axis may be about 3 inches and on the R axis about 4.5 to 5.0 inches.

For example, the auxiliary carousel 64 holds 32 MEIA cartridges 68 and has a diameter of approximately 9.5 inches. The auxiliary carousel 64 moves the MEIA cartridges 68 between various stations including the second transfer pipette device mechanism pipette point, the MUP distribution station 72, the MEIA wash station 70 and the MEIA reader 74 and the MEIA cartridge ejection point 62. The temporary carousel 64 is driven by a stepper motor and supported by three wheels, one wheel being on the Z-axis height control at the cartridge insertion point, the second wheel at the dropper point, and the third wheel at the MEIA reader, to maintain the temporary carousel 64 within desired geometric proportions with respect to these different functions.

MEIA cartridges 68 are loaded into a cartridge hopper 66 which feeds the MEIA cartridges 68 into the auxiliary carousel 64. Automatic feeding of the MEIA cartridges 68 is provided with an appropriate height adjustment of the cartridge 68 into the auxiliary carousel 64 as required by the MEIA reading process. The cartridge hopper 66 feeds the individual cartridges 68 to the auxiliary carousel 64 and changes the alignment axis of the cartridge 64 from horizontal to vertical by an automatic means. Removal of the MEIA cartridges 68 is accomplished through the use of an ejector 62 which operates by means of an ejector rod and pushes the MEIA cartridge 68 out of the auxiliary carousel 64 which then falls into a solid waste container.

Buffer supply stations are shown in Figure 14 which is a cross-sectional plan view of the apparatus showing the housing frame 14, the front end carousel 4 in partial view and a power supply element 192 together with the diluent system or buffer pressurizer 194. A supply bottle 196 as well as solid waste containers 198 and liquid waste containers 200 for receiving processed liquids and solid waste are also mounted in the lower housing of the frame 16.

A schematic view illustrating the ambient air flow and temperature control system is shown in Figure 15, where fresh air 204 enters and hot air exits at outlet 206. The air flow 202 is indicated by arrows and the controlled ambient air flow pattern 214 is provided with at least one heater element 208 and a fan element 210. At least one temperature sensor 212 is provided for controlling the air temperature and can be correlated with the air flow control 202.

The MEIA cartridge 68 is shown in a side elevation view in Fig. 16. The MEIA cartridge 68 has a funnel neck 216 and a cartridge opening 218. The MEIA cartridge 68 contains a carrier matrix material 222.

A MEIA cartridge 68 and a cartridge hopper 66 are shown in side elevation in Fig. 17. The MEIA cartridges are positioned horizontally in the cartridge hopper 66 and are actuated from the bottom of the V-shaped cartridge hopper 66 one at a time by a cartridge feeder 222. The cartridge feeder apparatus has a cartridge cam block 224 and a cartridge alignment ejector 226 which functions by means of a cartridge alignment pin 228 and a cartridge alignment pin 230 to provide the MEIA cartridge 68 in a vertical orientation for insertion into the auxiliary carousel 64. The alignment pins 228 and 230 are shown in Fig. 18 which is an isolated side cross-sectional view of the MEIA cartridge feeder cartridge alignment mechanism. The MEIA cartridge 68 is shown in Fig. 18 in an enlarged view as shown in the cartridge alignment pin 228 and cartridge alignment pin 230. Cartridge alignment pin 230 is shown engaged at a location 232 against the base 236 of MEIA cartridge 68 while cartridge alignment pin 228 is shown in engagement location 234 of cartridge throat portion 216. Upon removal of these pins from the engagement locations, MEIA cartridge 68 is released from the bottom portion first; ie, removal of cartridge alignment pin 230 thus allows the bottom of a cartridge 68 to fall downward by gravity before releasing the top of the cartridge which is engaged by cartridge alignment pin 228 in cartridge throat 216. The rounded or semi-circular retaining surfaces of the alignment pin permit the bottom of the MEIA cartridge to be released and the funnel neck portion 216 to roll off the cartridge alignment pin 228. The vertically aligned MEIA cartridge 68 is then inserted into the auxiliary carousel 64 at a controlled height by the action of an insertion cam means 227 as shown in Fig. 17. A side view of a MEIA cartridge ejection device 62 is shown in Fig. 19. The cartridge ejection device 62 operates by means of an ejection rod 240 and may be operated by a manual or automatic drive means 242. The ejected MEIA cartridge is ejected through an ejection opening into a solid waste container 198.

A functional block diagram of the optical signal processor of the device is provided in Fig. 20, wherein the signal from the FPIA optics 248 is fed to a DSP A/D 250, which also sends a serial bus signal 252 from an optical signal processor 8-bit microcontroller 254. The controller 254 is connected to computing elements by 256. A signal from the MEIA optics 258 is fed to a DSP A/D element 260, which also sends a serial bus signal 262 from the controller 254. The signal is fed to the FPIA optics by 264 from a high voltage power supply 266 and a serial bus connected between the microcontroller 254 and the optical power supply board 270A. The FPIA tungsten lamp power supply 270 is in electrical connection with the FPIA optics 272. The signal is transmitted to the MEIA optics through 274 from the high voltage power supply 276 which is connected by means of the serial bus 268 to the microcontroller 254 and the MEIA mercury arc lamp power supply 280. The MEIA mercury arc lamp power supply 280 is in electronic connection to the MEIA optics through 282.

A schematic view of the FPIA optical system 284 is shown in Figure 21. The FPIA optical system 284 includes a tungsten halogen source lamp 286 that focuses light through a heat reflector 288, an aperture 290 and a heat absorber 292 onto a lens 293 for introduction into an excitation filter 294. The light energy is then contacted by a beam splitter 296 which provides a portion of the beam to a polarizer 298 and a liquid crystal 300. The light passes further into another lens 301 before being focused onto the cuvette 140 containing the FPIA reaction mixture. The light is emitted from the cuvette by means of a lens means 303 before entering an emission filter 302. The light reflected from the emission filter 302 passes through a polarizer 304 before it passes to a focusing lens 306 and is focused for delivery to a photomultiplier 308. The beam splitter 296 splits a portion of the light from the original source by means of a lens 310 into a reference detector 312, which in turn controls the tungsten halogen source lamp.

A schematic view of the FPIA read sequence 314 is shown in Figure 22. The FPIA read sequence 314 has a pre-read time 316 which is divided into a carousel movement time 318 and a carousel settling time 320. The sub-read interval 340 is divided into a horizontal sub-read 342, an A/D converter settling time 344 and a liquid crystal activation time 346. A vertical sub-read interval is designated 348 and includes the A/D converter settling time 350. The liquid crystal rest time is designated 352. The liquid crystal rest time is divided into a pre-read time sequence. A high voltage settling time 324 is further represented by the lamp settling time 326 which shows the lamps in a mild glow activation 328 and a fully lit activation 330. The activities of the FPIA read sequence 314 provide for activities wherein the scheduling windows 332 are activated as exemplified by the read preparation 334, the read parameter 336 during which the lamps are fully lit, and the collection results 338 during the lamp settling time and the liquid crystal rest time 352.

Fig. 24 is a schematic view of the MEIA optical system assembly 64. A MEIA light source is provided by a mercury arc lamp 364 which directs the light through an excitation filter 362 to a filter reflector 360 before passing it into the MEIA cartridge 68 by means of the lens 358. The reflected fluorescent light is returned to a photomultiplier tube 374 by means of the filter 360 after passing through a wide band-gauge emission filter 370 and a narrow band-gauge emission filter 372. A portion of the light energy from the mercury arc lamp 364 passes directly through the filter 360 to a band-pass filter 368 before affecting the photodiode 366.

A schematic MEIA read sequence view is shown in Figure 25, wherein the MEIA read sequence 37 has a pre-read time 378 that includes a carousel movement time 380 and a carousel settling time 382. The high voltage settling time is indicated by the graph 384 which coincides with the lamp settling time 386 showing the mild lamp glow 388 and the full lamp illumination 390. The MEIA read sequence 376 is engaged in scheduling windows 392 including the read preparation 394, the read parameter 396, and the collection results 398. The actual MEIA read sequence 376 includes a sub-read interval 400 that includes a sub-read operation 402 and a rest period 404. Another segment of the MEIA read sequence 376 is followed by the sub-read interval 406 including the sub-read number 408 and the rest period 410 with additional sub-reads 412 as indicated by the number 3. by means of (N-1) and a partial subinterval 414 including the sub-reading number N-416. The next possible reading time is indicated with 418.

To ensure consistent, rapid resuspension and continuous reagent mixing with the least possible operator intervention, reagents are automatically and periodically mixed during instrument operation each time a new reagent packet is added to the reagent carousel. This automated mixing can be achieved by moving the reagent carousel backwards and forwards with asymmetric pauses and is completed in approximately 1-2 minutes. The carousel acceleration speed, distance traveled and pause asymmetry are optimized to provide the fastest reagent resuspension without foaming or bubbling within the range of fill volumes used on the instrument.

Automated reagent mixing provides the following advantages: The operator does not need to manually mix (e.g., by inverting or shaking) reagents that have been stored on the instrument prior to their placement on the instrument. This allows reagents to be loaded onto the instrument more quickly and with minimal operator intervention. The tendency of reagents to foam or bubble is less with automated mixing than with manual mixing such as inverting. Foaming and bubbling are detrimental to instrument function and can negatively affect assay performance. Automated mixing ensures that reagents are always adequately mixed and consistently mixed. Occasional automated mixing during instrument operation keeps reagents in suspension throughout, eliminating the need for the operator to periodically remove reagent packs to mix reagents. Under certain circumstances, automated mixing can remove bubbles present at the beginning of mixing. A detailed description of the kitting and process activities according to the invention are shown below for the FPIA workflows; the system description of the Procedural activities for a phenobarbital assay; and MEIA workflows for a CEA assay.

It should be appreciated that the following description includes a schematic explanation of the various functions and steps involved in the preferred methods of the automated analytical system of the invention, which functions and methods, as will also be appreciated by those skilled in the art, are directed under computer control using various types of mathematical algorithms and associated computer software depending on the particular menu of assays to be performed on the instrument.

Although the assay cuvette of the present invention has been described herein for use with various automated analytical systems, it should be understood that the assay cuvette can be used when the assay formats described herein are performed manually.

The present invention will now be illustrated by means of the following examples - but it is not intended to be limited thereto.

example 1

Comparison of Plastic Cuvettes to Glass Analysis Cuvettes The equivalence of plastic cuvettes of the present invention to the glass cuvettes was demonstrated by comparing acrylic cuvettes prepared in accordance with the present invention to Abbott Tdx® glass cuvettes. Such a comparison was made on an Abbott Tdx® analyzer with the following modifications:

(i) Rhodamine 110 (Kokak, Rochester, N.Y.) in 75% glycerol was used as an optical standard solution; and

(ii) the standard photo verification protocol outlined in the Abbott Tdx® Analyzer Manual has been modified to allow the use of all twenty (20) carousel positions with a twelve (12) minute warm-up period.

The results of such a comparison are shown in Fig. 30, which shows the mP average of the acrylic cuvettes according to the present invention to the mP average of the glass cuvettes, and in Figure 31 which compares the ratio of the mP average of the plastic cuvettes according to the present invention to the mP average of the glass cuvettes - both in Table 1 and Table 2 below. As shown in Figure 30, the acrylic cuvettes from six different cuvette preparation lots were analyzed (Lot 1 = Abbott Tdx Analyzer Run Numbers 1-10; Lot 2 = Abbott Tdx Analyzer Run Numbers 11-13; Lot 3 = Abbott Tdx Analyzer Run Numbers 14-17; Lot 4 = Abbott Tdx Analyzer Run Numbers 18-27; Lot 5 = Abbott Tdx Analyzer Run Numbers 28-47; and Lot 6 = Abbott Tdx Analyzer Run Numbers 48-51); and, as shown in Fig. 31, the mP average therefrom was essentially equivalent to the glass cuvettes. Table 1 Variability of the acrylic cuvettes Table 2 Acrylic cuvettes in relation to glass cuvettes

Example 2 Assay comparison of acrylic cuvettes with glass cuvettes

(a) Fluorescence polarization immunoassay

Fluorescence polarization immunoassays for a c-reactive protein (Fig. 32), opiate (Fig. 33) and theophylline (Fig. 34) were performed on an Abbott Tdx analyzer using Abbott Tdx C-reactive protein assay reagents, Abbott Tdx opiate assay reagents and Abbott Tdx theophylline assay reagents. Each assay was performed separately in acrylic cuvettes according to the present invention and in Abbott Tdx glass cuvettes.

(b) Extinction assay

An absorbance assay for glucose (Figure 35) was performed on an Abbott VP analyzer using Abbott VP glucose assay reagents. The assay was performed using an acrylic cuvette of the present invention and an Abbott multicuvette.

Example 3 Description of the cement and process area activities for the FPIA SYSTEM DESCRIPTION OF THE PUTTY AREA FOR A PHENOBARIBITAL ASSAY A. REQUIREMENTS

1. An analyzer is in standby/ready mode when the sample is loaded. The system has been initialized before (all motors are returned to the starting position, syringes and pumps are emptied, all electronics and all sensors are checked).

2. Waste was emptied, diluent, MEIA buffer, MUP and "Quat" liquid main consumables were checked for adequacy.

3. All consumable inventory files have been updated.

B. PREPARATION STEPS

1. The user loads an empty reaction vessel (RC) into the RC carousel.

2. To load a reagent pack(s), the user must first bring the front end carousels to a stop. The system will complete the cementing of the current test and transfer the test to the process area.

3. The user opens the reagent carousel cover, loads the reagent pack(s) into the reagent carousel, closes the reagent carousel cover and resumes work at the front end.

4. The instrument will automatically scan all reagent packs in the instrument to check the reagent status.

(a) Each reagent pack is positioned in front of the reagent pack bar code reader by rotating the reagent carousel.

(b) The reagent pack barcode reader reads the barcode to identify the assay type and carousel position.

(c) If the barcode is unreadable, the system will request a barcode correction.

(d) If the barcode is good or the correction is completed, the system will check the system inventory. The user will be informed if the pack is found empty, invalid or expired. Once the reagent pack is found to be good, it is ready for use.

C. REQUEST A TEST

1. The user has two options to request a test or group of tests on one or more patient samples.

(a) The user may download the test request loading list from a host computer to generate an order list.

(b) The user enters test prompts or creates an order list directly on the system.

2. If sample cups (no barcode) are used, the following scenario occurs:

(a) The user refers to the order list for the segment ID and position number to place a sample.

(b) The user loads a sample cup into the location in the segment to be referenced.

(c) The user transfers the patient sample from the blood collection tube into the sample cup.

(d) The segment is placed in the sample carousel.

(e) An indication is given to the instrument that the samples have been loaded.

(f) The device checks the consumable system inventory, waste status, calibration status, etc.

(g) The sample carousel rotates the segment towards the segment identification reader.

(h) The device reads the segment identification.

3. If primary tubes (with barcode) are used, the following scenario takes place (two types of supports are used for the primary tubes: one of the tubes is 75 mm high and a second tube is 100 mm high):

(a) The user loads the primary tube into the next available segment location on the sample carousel.

(b) An indication is given to the instrument that the samples are available for processing.

(c) The device checks the consumables inventory, waste status, calibration status, etc.

D. PLANNING A TEST

1. When the sample is presented to the pipettor, the system attempts to schedule the ordered tests scheduled on that sample. Each ordered test for the sample is scheduled independently.

(b) The system checks for appropriate inventory (reagent packs, cartridges, buffers, MUP), system resources and assay time to perform the test.

(c) The system checks the valid calibration or the orders for it on the order list.

(d) If all test requirements are met, the test is scheduled for processing.

(e) If all test requirements are not met, the test request is moved to the exception list. Once the test requirements are met, the user moves the test request back to the order list.

2. If a test has been scheduled, the system moves it to the processing list and attempts to schedule additional tests ordered for that sample.

3. When all tests for the current sample have been cemented, the system advances to the next sample on the sample carousel.

E. KITTEN OF A TEST

1. Once a test is scheduled, it is immediately kitted. (No tests are kitted until the scheduler ensures that the test can be immediately transferred to the process carousel and processed within the time requirements of the assay.)

2. The RG carousel is rotated clockwise until an RG is detected in the pipette axis position.

3. The reagent pack carousel is rotated until the reagent pack for the ordered test is at the actuator position. The actuator opens the reagent cartridge lids and the reagent pack carousel is then rotated until a reagent pack for the ordered test is at the pipette axis position. After all Once the pipetting steps have been completed, the reagent pack carousel is rotated back to the actuator position where the reagent cartridge lids are closed.

4. The sample carousel is rotated until the sample cup (or primary tube) is in the pipette axis position.

5. The pipette is always in the "HOME" position (The pipette R-axis is parked over the wash point and the pipette Z-axis is in the Z-clear position) when not in use.

6. Sample cement.

(a) Sample aspirate.

(i) The syringe aspirates "X" uL of air at a rate of "X" uL/sec.

(ii) The R-axis of the pipette is moved over the sample cup.

(iii) The pipette Z-axis is moved down to the upper Z-position.

(iv) The LLS is activated to ensure that no fluid is currently being detected.

(v) The pipette Z-axis is moved downward at a constant speed until fluid is detected or until the Z-Asp limit is reached (It is assumed that fluid is detected).

(vi) Based on the Z-height position at which the fluid is sensed and the Z-height/volume table, the system calculates the volume of fluid in the container and compares it to the volume specified in the pipetting description. If there is sufficient volume in the container, the aspiration sequence is started (If there is not sufficient volume, the test is aborted and the test prompt is moved to the exception list. The exception list provides an operator with the message about the tests that cannot be completed).

(vii) The following is done simultaneously until the total volume of sample required is aspirated:

(1) The pipette Z-axis motor is operated at a speed moved downwards by "X" steps/second.

(2) The syringe motor aspirates "X" uL at a speed of "X" ul/sec.

(3) The LLS is checked to ensure that the probe in the liquid level sense (LLS) is still held off. The pipette Z-axis is moved up to the Z-clear position.

(4) The pipette R-axis is moved over the RG sample container.

(5) The pipette Z-axis is moved downwards to the distribution position within the RG sample container.

(6) The syringe dispenses "X" uL of sample at a rate of "X" ul/sec.

(7) The pipette Z-axis is moved up to the Z-clear position.

(b) Probe rewash

The probe is washed to ensure that it is free of contamination. It should be understood that all pipette activities (both in the kit and process areas) are followed by a probe post-wash to minimize carryover from one fluid aspirate to another. In some cases, if necessary, a probe pre-wash may precede pipette activities to ensure the validity of the next fluid aspirate. For this assay description, it is assumed that only one post-wash is used.

(i) The inside of the probe is first washed.

(1) The pipette R-axis is moved over the waste area.

(2) The pipette Z-axis is moved down to a suitable location within the waste area.

(3) The wash valve is opened for the time period specified in the assay protocol.

(4) The washing valve is closed.

(5) The pipette Z-axis is moved upwards into the Z- moved to the extinguishing position.

(ii) The outside of the probe is washed next.

(1) The pipette R-axis is moved over the wash cup.

(2) The pipette Z-axis is moved downwards to the washing position within the wash cup.

(3) The wash valve is opened for the time period specified in the assay protocol.

(4) The washing valve is closed.

(iii) The pipette is returned to its "HOME" position.

7. Popper kitting (“popper” is defined as a substance that generally eliminates interfering substances in assays, such as those described in U.S. Patent 4,492,762, issued January 8, 1985, the contents of which are incorporated herein by reference).

(a) Popper sucking.

(i) The syringe aspirates "X" uL of air at a rate of "X" ul/sec.

(ii) The pipette R-axis is moved over the Popper reagent bottle in the reagent pack.

(iii) The pipette Z-axis is moved downwards to the upper Z-position.

(v) The pipette Z-axis is moved downward at a constant speed until the fluid is aspirated or until the lower Z-aspiration (Z-Asp) limit is reached (fluid is assumed to be aspirated).

(vi) Based on the Z-height position at which the fluid is sensed and the Z-height/volume table, the system calculates the volume of fluid in the container and compares it to the volume specified in the pipetting description. If the volume in the container is sufficient, the aspiration sequence is initiated (if the volume is insufficient, the test is aborted and the test prompt is moved to the exception list)

(vii) The following occurs simultaneously until the total volume of the required popper is sucked:

(1) The pipette Z-axis motor is moved downward at a speed of "X" steps/sec. (2) The syringe aspirates "X" uL at a speed of "X" ul/sec.

(3) The LLS is checked to ensure that the probe is still in the fluid.

(4) The LLS is deactivated.

(5) The pipette Z-axis is moved up to the Z-clear position.

(6) The pipette R-axis is moved over the RG reagent container 1.

(7) The pipette Z-axis is moved downward to the distribution position within the RG reagent container 1.

(8) The syringe dispenses "X" uL of popper at a rate of "X" ul/sec.

(9) The pipette Z-axis is moved up to the Z-clear position.

(b) Probe rewash.

The probe is washed again to ensure that it is free from contamination as described in Section 6 (Sample Kitting).

B. Antiserum kitten

(a) Antiserum aspirate

(i) The syringe aspirates "X" uL of air at a rate of "X" ul/sec.

(ii) The pipette R-axis is moved over the antiserum reagent bottle in the reagent pack.

(iii) The pipette Z axis is moved downward to the position above Z.

(iv) The LLS is activated to ensure that no liquid is currently being detected.

(v) The pipette Z-axis is moved downward at a constant speed until fluid is detected or the Z-Asp limit is reached (assuming fluid is detected).

(vi) Based on the Z-height position at which the fluid is detected and the Z-Height/Volume table, the system calculates the volume of fluid in the container and compares it to the volume specified in the pipetting description. If the volume in the container is sufficient, the aspiration sequence is initiated (if the volume is insufficient, the test is aborted and the test request is moved to the exception list).

(vii) The following is done simultaneously until the total volume of antiserum required is aspirated:

(1) The pipette Z-axis motor is moved down at a speed of "X" steps/sec.

(2) The syringe aspirates "X" microliters (uL) at a rate of "X" ul/sec. The LLS is checked to ensure that the probe is still in the fluid.

(3) The LLS is deactivated.

(4) The pipette Z-axis is moved up to the Z-clear position.

(5) The pipette R-axis is moved over the RG reagent container 2.

(6) The pipette Z-axis is moved downward to the distribution position within the RG reagent container 2.

(7) The syringe dispenses "X" uL of antiserum at a rate of "X" ul/sec.

(8) The pipette Z-axis is moved up to the Z-clear position.

(b) Probe rewash

The probe is washed again to ensure that it is free from contamination as described in Section 6 (Sample Sealing).

9. Indicator kitting

(a) Indicator aspirate

(i) The syringe aspirates "X" uL of air at a rate of "X" ul/sec.

(ii) The pipette R-axis is moved over the indicator reagent bottle in the reagent pack.

(iii) The pipette Z axis is moved downward to the position above Z.

(iv) The LLS is activated to ensure that no fluid is currently being detected.

(v) The pipette Z-axis is moved downward at constant speed until fluid is sensed or until the Z-Asp limit is reached (fluid is assumed to be sensed).

(vi) Based on the Z-height position at which the fluid is sensed and the Z-height/volume table, the system calculates the volume of fluid in the container and compares it to the volume specified in the pipetting description. If the volume in the container is sufficient, the aspiration sequence is initiated (if the volume is insufficient, the test is aborted and the test request is moved to the exception list)

(vii) The following occurs simultaneously until the total volume of indicator required is aspirated:

(1) The pipette Z-axis motor is moved downward at a speed of "X" steps/sec. (2) The syringe aspirates "X" uL at a speed of "X" ul/sec.

(3) The LLS is checked to ensure that the probe is still in the fluid.

(4) The LLS is deactivated.

(5) The pipette Z-axis is moved up to the Z-clear position.

(6) The pipette R-axis is moved over the RG reagent container 3.

(7) The pipette Z-axis is moved downward to the distribution position within the RG reagent container 2.

(8) The syringe dispenses "X" uL of indicator at a rate of "X" ul/sec.

(9) The pipette Z-axis is moved up to the Z-clear position.

(b) Sample washing

The probe is washed again to ensure that it is free from contamination, as described in Section 6 (Sample Kitting).

F. TRANSFERRING THE REACTION VESSEL (RG) TO THE PROCESS AREA

1. The RG carousel is rotated into the transfer station.

2. The process carousel is rotated so that the empty position is aligned with the transfer position.

3. The transfer mechanism O-axis is rotated to the sample entry area.

4. The transfer mechanism R-axis grabs the RG and pulls it into the transfer mechanism

5. The transfer mechanism O-axis is rotated so that the RG is aligned with the empty space on the process carousel.

6. The RG is loaded onto the process carousel.

SYSTEM DESCRIPTION OF THE FPIA PROCESS AREA FOR PHENOBARBITAL

A. Wait for the temperature equilibration time and evaporation window to expire.

B. THE FIRST PIPETTE ACTIVITY (preparation of the sample blank containing the diluted sample and the popper).

1. The incubation timer is set according to the assay file specification.

2. Precision Diluent Aspirate. The following activities are performed simultaneously.

(a) The syringe aspirates "X" uL at a rate of "X" ul/sec.

(b) The washing valve is opened.

(c) Wait "n" seconds.

(d) Wash valve is closed.

3. Sample aspirate.

(a) The pipette R-axis is moved over the RG sample container.

(b) The LLS is activated to ensure that no liquid is currently detected.

(c) The pipette Z-axis is moved downward at a constant speed until a fluid is detected OR until the Z-Asp limit is reached (it is assumed that the fluid is detected).

(d) Based on the Z-height position at which the fluid is sensed and the Z-height/volume table, the system calculates the volume of fluid in the container and compares it to the volume specified in the pipetting description. If the volume in the container is sufficient, the aspiration sequence is initiated (if the volume is insufficient, the test is aborted and the test request is moved to the exception list).

(e) The following occurs simultaneously until the total volume of sample required is aspirated:

(i) The pipette Z-axis motor is moved downward at a speed of "X" steps/sec.

(ii) The syringe aspirates "x" uL of sample at a rate of "X" ul/sec.

(iii) The LLS is checked to ensure that the probe is still in the fluid.

(iv) The LLS is deactivated.

(v) The pipette Z axis is moved up to the position above Z.

4. The diluent/sample is dispensed into the RG pre-dilution container.

(a) The pipette R-axis is moved over the RG prediluent container.

(b) The pipette Z-axis is moved downward to the dispensing position within the RG pre-diluent container.

(c) The syringe dispenses "X" uL of diluent/sample at a rate of "X" ul/sec.

(d) The pipette Z-axis is moved up to the Z-erase position.

5. Rinse the probe.

The probe is washed again to ensure that it is free from contamination as described in Section 6 (Sample Kitting).

6. Precision diluent aspirate. The following activities are performed simultaneously:

(a) The syringe aspirates "X" uL at a rate of "X" ul/sec.

(b) The washing valve is opened.

(c) Wait "n" seconds.

(d) The washing valve is closed.

7. Popper aspirate.

(a) The pipette R-axis is moved over the RG reagent (popper) container.

(b) The LLS is activated to ensure that no fluid is currently being detected.

(c) The pipette Z-axis is moved downward at constant velocity until fluid is detected or until the Z-Asp limit is reached (fluid is assumed to be detected).

(d) Based on the Z-height position at which the fluid is sensed and the Z-height/volume table, the system calculates the volume of fluid in the container and compares it to the volume specified in the pipetting description. If the volume in the container is sufficient, the aspiration sequence is initiated (if the volume is insufficient, the test is aborted and the test request is moved to the exception list).

(e) The following occurs simultaneously until the total volume of popper required is sucked:

(i) The pipette Z-axis motor is moved downward at a speed of "X" steps/sec.

(ii) The syringe aspirates "x" uL at a rate of "X" ul/sec.

(iii) The LLS is checked to ensure that the probe is still in the fluid.

(iv) The LLS is deactivated.

(v) The pipette Z axis is moved up to the position above Z.

6. Diluted sample aspirate.

(a) The pipette R-axis is moved over the RG prediluent container.

(b) The LLS is activated to ensure that no fluid is currently being sensed.

(c) The pipette Z-axis is moved downward at constant speed until fluid is detected or until the Z-Asp limit is reached (fluid is assumed to be detected).

(d) Based on the Z-height position at which the fluid is sensed and the Z-height/volume table, the system calculates the volume of fluid in the container and compares it to the volume specified in the pipetting description. If the volume in the container is sufficient, the aspiration sequence is initiated (if the volume is insufficient, the test is aborted and the test request is moved to the exception list).

(e) The following occur simultaneously until the total volume of sample required is aspirated: (i) The pipette Z-axis motor is moved downward at a speed of "X" steps/sec. (ii) The syringe aspirates "x" uL at a speed of "X" uL/sec.

(iii) The LLS is checked to ensure that the probe is still in the fluid.

(iv) The LLS is deactivated.

(v) The pipette Z axis is moved up to the position above Z.

11. Diluted sample/Popper diluent dispensed in the RG cuvette.

(a) The pipette R-axis is moved towards the RG cuvette position.

(b) The pipette Z-axis is moved downwards into the Distribution position in the RG cuvette.

(c) The syringe dispenses "X" uL of diluted sample/popper/diluent at a rate of "X" uL/sec.

(d) The pipette Z axis is moved up to the position above Z.

12. Rinse the probe.

The probe is washed again to ensure that it is free of contamination, as described in Section 6 (Sample Kitting), to complete the first pipette activity.

C. PREPARATION FOR BLANK READING

When the incubation timer expires, the following activities are started:

1. The FPIA reader is prepared to perform a reading operation; the lamp intensity is changed from the idle state to the burning state.

2. The photomultiplier tube (PMT) gain is set.

D. BLANK READING PROCESS (BACKGROUND)

1. The incubation timer is set according to the assay file descriptions.

2. The process carousel is rotated so that the RG is at the reading station.

3. The horizontal strength is read over "X. XX" seconds.

4. The crystal is tilted for the vertical reading.

5. Wait "n" seconds for the crystal to calm down.

6. The vertical intensity is read for over "X. XX" seconds. 7. The raw readings are converted by the optics microprocessor into standardized readings (light intensity/lamp intensity hitting the detector).

8. The background reads are saved. 9. The system calculates EMPTY 1 to complete the empty read.

10. The next activity will start when the incubation timer expires.

E. SECOND PIPETTE ACTIVITY (for the reaction between a diluted sample, popper, indicator and antiserum).

1. The incubation timer is set according to the assay file descriptions.

2. Precision thinner aspirate.

(a) The following activities are carried out simultaneously.

(i) The syringe aspirates "X" uL at a rate of "X" ul/sec.

(ii) The washing valve is opened.

(iii) Wait "n" seconds.

(iv) The washing valve is closed.

3. Antiserum aspirate.

(i) The pipette R-axis is moved over the RG Reagent 2 (Antiserum) container.

(ii) The LLS is activated to ensure that no fluid is currently being detected.

(iii) The pipette Z-axis is moved downward at constant velocity until a fluid is detected OR until the Z-Asp limit is reached (it is assumed that the fluid is detected).

(iv) Based on the Z-height position at which the fluid is sensed and the Z-height/volume table, the system calculates the volume of fluid in the container and compares it to the volume specified in the pipetting description. If the volume in the container is sufficient, the aspiration sequence is initiated (if the volume is insufficient, the test is aborted and the test request is moved to the exception list)

(v) The following is done simultaneously until the total volume of antiserum required is aspirated:

(1) The pipette Z-axis motor is moved downward at a speed of "X" steps/sec. (2) The syringe aspirates "x" uL at a speed of "X" ul/sec.

(3) The LLS is checked to ensure that the probe is still in the fluid.

(4) The LLS is deactivated.

(5) The pipette Z axis is moved up to the position above Z.

4. Indicator aspirate.

(a) The syringe aspirates "X" uL of air at a rate of "X" ul/sec.

(b) The pipette R-axis is moved over the RG Reagent 3(Indicator) container.

(c) The LLS is activated to ensure that no fluid is currently being detected.

(d) The pipette Z-axis is moved downward at a constant speed until a fluid is detected OR until the Z-Asp limit is reached (the fluid is assumed to be detected).

(e) Based on the Z-height position at which the fluid is sensed and the Z-height/volume table, the system calculates the volume of fluid in the container and compares it to the volume specified in the pipetting description. If the volume in the container is sufficient, the aspiration sequence is initiated (if the volume is not sufficient, the test is aborted and the test request is moved to the exception list).

(f) The following is done simultaneously until the total volume of the required indicator is aspirated:

(1) The pipette Z-axis motor is moved down at a speed of "X" steps/sec.

(ii) The syringe aspirates "x" uL at a rate of "X" ul/sec.

(iii) The LLS is checked to ensure that the probe is still in the fluid.

(iv) The LLS is deactivated.

(v) The pipette Z axis is moved up to the position above Z.

5. Diluted sample aspirate.

(a) The pipette R-axis is moved over the RG prediluent container.

(b) The LLS is activated to ensure that no fluid is currently being detected.

(c) The pipette Z-axis is moved downward at a constant speed until a fluid is detected OR until the Z-Asp limit is reached (it is assumed that the fluid is detected)

(d) Based on the Z-height position at which the fluid is sensed and the Z-height/volume table, the system calculates the volume of fluid in the container and compares it to the volume specified in the pipetting description. If the volume in the container is sufficient, the aspiration sequence is initiated (if the volume is not sufficient, the test is aborted and the test request is moved to the exception list).

(e) The following are performed simultaneously until the total volume of the required diluted sample is aspirated:

(1) The pipette Z-axis motor is moved down at a speed of "X" steps/sec.

(2) The syringe aspirates "x" uL at a rate of "X" ul/sec.

(3) The LLS is checked to ensure that the probe is still in the fluid.

(4) The LLS is deactivated.

(5) The pipette Z axis is moved up to the position above Z.

6. Diluted sample/indicator/aspirate/antiserum/diluent dispensed into the RG cuvette.

(a) The pipette R-axis is moved towards the RG cuvette position.

(b) The pipette Z-axis is moved down to the distribution position in the RG cuvette.

(c) The syringe dispenses "X" uL of diluted sample/indicator/air/antiserum/diluent at a rate of "X" uL/sec.

(d) The pipette Z axis is moved upwards to the position indicated by Z current position.

7. Wash the samples.

The sample is washed again to ensure that it is free of contamination, as described in Section 6 (Sample Kitting), to complete the second pipette activity.

8. The next activity begins when the incubation timer has expired.

E. FINAL READING PREPARATION

1. The FPIA reader is prepared to perform a reading; the lamp intensity is changed from the idle state to the burning state.

2. The PMT gain is adjusted.

F. LAST READING

1. The process carousel is rotated so that the RG is at the reading station.

2. The horizontal strength is read over "X. XX" seconds.

3. The crystal is tilted for the vertical reading.

4. The system delays for "n" seconds until the crystal settles.

5. The vertical strength is read over "X. XX" seconds.

6. The unprocessed readings are converted by the optics microprocessor into standardized readings (light intensity/lamp intensity hitting the detector).

7. The reading processes are saved.

8. The system calculates the NET strength (1) and the millipolarization (mP).

9. The mP value is inserted into the calibration curve to give a concentration result.

6. RG UNLOADING (this activity takes place when the assets are not in use). The following is carried out simultaneously:

1. The process carousel is rotated so that the empty space is at the transfer station. The transfer mechanism 0 axis is moved to the process carousel.

2. The RG is gripped by the transfer mechanism R-axis and pulled into the transfer mechanism. 3. The transfer mechanism 0-axis is rotated so that the RG is aligned with the waste container. 4. The RG is pushed into the waste container.

Example 4 Description of kitting and process area activities for the MEIA SYSTEM DESCRIPTION OF THE KITTING AREA FOR THE CEA ASSAY A. REQUIREMENTS

1. The analyzer is in Ready/Ready mode when the sample is loaded. The system has been previously initialized (all motors are set to the home position, the syringe and pumps are emptied, and all electronics and sensors are checked).

2. Waste was emptied, diluent, MEIA buffer, MUP and "Quat" liquid core consumables were checked for adequate volume.

3. The cartridges have been placed in the hopper and are available for loading onto the temporary carousel if required (for MEIA samples only).

4. All consumable inventory files have been updated.

B. PREPARATION STEPS

1. The user loads empty reaction tubes into the RG carousel.

2. To load a reagent pack(s), the user must first stop the front end carousel. The system will complete the kitting of the current test and Transfer test to the process area.

3. The user opens the reagent carousel, loads the reagent pack(s) into the reagent carousel, closes the reagent carousel lid, and picks up the front end.

4. The instrument automatically scans all reagent packs in the instrument to check the reagent status.

5. Each reagent pack is positioned in front of the reagent pack barcode reader by rotating the reagent carousel.

6. The reagent pack barcode reader reads the barcode to identify the assay type and carousel position. If the barcode is unreadable, the system will request a barcode correction.

7. If the barcode is good or the correction is finished, the system will check the system inventory. The user will be informed if the pack is found empty, invalid or expired. Once the reagent pack is found to be good, it is ready for use.

C. REQUEST A TEST

1. The user has two options to request a test or group of tests on one or more patient samples.

(a) The user may download the test load request list from a host computer to generate an order list.

(b) The user enters test prompts or creates an order list directly on the system.

2. If sample cups (no barcode) are used, the following scenario occurs:

(a) The user refers to the order list for the segment ID and position number to place a sample.

(b) The user loads a sample cup into the location in the Segment referred to.

(c) The user transfers the patient sample from the blood collection tube into the sample cup.

(d) The segment is placed in the sample carousel.

(e) An indication is given to the instrument that the samples have been loaded.

(f) The instrument checks consumable inventory, waste status, sample calibration, etc.

(g) The sample carousel rotates the segment to the segment identification reader.

(h) The device reads the segment identification.

3. When primary tubes (with barcode) are used, the following scenario occurs:

(a) The user loads the primary tube into the next available segment location on the sample carousel (two types of carriers are used for the primary tube: one for 75 mm high tubes and a second for 100 mm high tubes).

(b) An indication is given to the instrument that the samples are available for running.

(c) The device rotates the segment towards the segment identification reader.

D. PLANNING A TEST

1. When the sample is presented to the pipettor, the system attempts to schedule the scheduled tests ordered on that sample. Each ordered test for the sample is scheduled independently.

(a) The system checks for appropriate inventory (reagent packs, cartridges, buffers, MUP), system resources and assay time to perform the test.

(b) The system checks the valid calibration or the orders for it on the order list.

(c) If all test requirements are met, the test is scheduled for processing.

(d) If not all test requirements are met, the test request is moved to the exception list. If the Once test requirements are met, the user moves the test request back to the order list. 2. Once a test has been scheduled, the system moves it to the processing list and attempts to schedule additional tests ordered for that sample.

3. When all tests for the current sample have been cemented, the system advances to the next sample on the sample carousel.

E. KITTEN OF A TEST

1. Once a test is scheduled, it is immediately cemented. (No tests are cemented until the scheduler ensures that the test can be immediately transferred to the process carousel and processed within the time requirements of the sample.)

2. The RG carousel is rotated clockwise until an RG is detected in the pipette axis position.

3. The reagent pack carousel is rotated until the reagent pack for the ordered test is at the actuator position. The actuator opens the reagent cartridge lids and the reagent pack carousel is then rotated until a reagent pack for the ordered test is at the pipette axis position.

After all pipetting steps have been completed, the reagent pack carousel is rotated back to the actuator position where the reagent cartridge lids are closed.

4. The sample carousel is rotated until the sample cup (or primary tube) is in the pipette axis position.

5. The pipette is always in the "HOME" position (The pipette R-axis is parked over the wash point and the pipette Z-axis is in the Z-clear position) when not in use.

6. Sample cement.

(a) Sample aspirate.

(i) The syringe aspirates "X" uL of air at a rate of "X" ul/sec.

(ii) The R-axis of the pipette is moved over the sample cup.

(iii) The pipette Z-axis is moved downward to the upper Z-location.

(iv) The pipette Z-axis is moved down to the Z-LLS position.

(v) The LLS is activated to ensure that no fluid is currently being detected.

(vi) The pipette Z-axis is moved downward at a constant speed until fluid is detected or until the Z-Asp limit is reached (It is assumed that fluid is detected).

(vii) Based on the Z-height position at which the fluid is sensed and the Z-height/volume table, the system calculates the volume of fluid in the container and compares it to the volume specified in the pipetting description. If there is sufficient volume in the container, the aspiration sequence is started (if there is insufficient volume, the test is aborted and the test prompt is moved to the exception list).

(viii) The following are performed simultaneously until the total volume of sample required is aspirated:

(1) The pipette Z-axis motor is moved down at a speed of "X" steps/second.

(2) The syringe motor aspirates "X" uL at a speed of "X" ul/sec.

(3) The LLS is checked to ensure that the probe is still in the fluid.

(4) The LLS is deactivated.

(5) The pipette R-axis is moved up to the Z-clear position.

(6) The pipette R-axis is moved over the RG sample container.

(7) The pipette Z-axis is moved downwards to the distribution position within the RG sample container.

(8) The syringe dispenses "X" WZ of sample at a rate of "X" ul/sec.

(9) The pipette Z-axis is moved up to the Z-clear position.

(b) Probe rewash

The probe is washed to ensure that it is free of contamination. It should be understood that all pipette activities in both the kit and process areas are generally followed by a probe post-wash to minimize carryover from one fluid aspirate to another. In some cases, if necessary, a probe pre-wash may precede the pipette activities to ensure the validity of the next fluid aspirate. For this assay description, it is assumed that only one post-wash is used.

(1) The inside of the probe is first cleaned.

(i) The pipette R-axis is moved over the waste area.

(2) The pipette Z-axis is moved down to a suitable position within the waste area.

(3) The wash valve is opened for the time period specified in the assay protocol.

(4) The washing valve is closed.

(ii) The pipette Z-axis is moved up to the Z-clear position.

(iii) The outside of the probe is cleaned next

(1) The pipette R-axis is moved over the wash cup.

(2) The pipette Z-axis is moved downwards to the washing position within the wash cup.

(3) The wash valve is opened for the time period specified in the assay protocol.

(4) The washing valve is closed.

(5) The pipette is returned to its "HOME" position.

7. Microparticle cements.

(a) Microparticle aspirate (microparticles are pipetted directly into the RG incubation vessel to save volume, as this is the most expensive MEIA reagent).

(i) The syringe aspirates "X" uL of air at a rate of "X" ul/sec.

(ii) The R-axis of the pipette is moved over the microparticle reagent bottle in the reagent pack.

(iii) The pipette Z-axis is moved downward to the upper Z-location.

(iv) The pipette Z-axis is moved down to the Z-LLS position.

(v) The LLS is activated to ensure that no fluid is currently being detected.

(vi) The pipette Z-axis is moved downward at a constant speed until fluid is detected or until the Z-Asp limit is reached (It is assumed that fluid is detected).

(vii) Based on the Z-height position at which the fluid is sensed and the Z-height/volume table, the system calculates the volume of fluid in the container and compares it to the volume specified in the pipetting description. If there is sufficient volume in the container, the aspiration sequence is started (if there is insufficient volume, the test is aborted and the test prompt is moved to the exception list).

(viii) The following occurs simultaneously until the total volume of microparticles required is aspirated:

(1) The pipette Z-axis motor is moved down at a speed of "X" steps/second.

(2) The syringe motor aspirates "X" uL at a speed of "X" ul/sec.

(3) The LLS is checked to ensure that the probe is still in the fluid.

(ix) The LLS is deactivated.

(x) The pipette Z-axis is moved up to the Z-clear position.

(xi) The pipette R-axis is moved over the RG incubation vessel.

(xii) The pipette Z-axis is moved downwards to the distribution position within the RG incubation vessel.

(xiii) The syringe dispenses "X" µL of microparticles at a rate of "X" µL/sec. The pipette Z-axis is moved up to the Z-clear position.

(b) Probe rewash

The probe is washed again to ensure that it is free from contamination as described in Section 6 (Sample Kitting).

8. Conjugate kitten

(a) Conjugate aspirate (conjugate, special wash fluid and/or sample diluent are pipetted into either the RG reagent containers or the RG pre-diluent container, depending on volume requirements).

(i) The syringe aspirates "X" uL of air at a rate of "X" ul/sec.

(ii) The R-axis of the pipette is moved over the conjugate reagent bottle in the reagent pack.

(iii) The pipette Z-axis is moved downward to the upper Z-location.

(iv) The pipette Z-axis is moved down to the Z-LLS position.

(v) The LLS is activated to ensure that no fluid is currently being detected.

(vi) The pipette Z-axis is moved downward at a constant speed until fluid is detected or until the Z-Asp limit is reached (It is assumed that fluid is detected).

(vii) Based on the Z-height position at which the fluid is acquired and the Z-height/volume table, the system calculates the volume of fluid in the container and compares it with the volume specified in the pipetting description. If there is sufficient volume in the container, the aspiration sequence is started (If there is insufficient volume, the test is aborted and the test prompt is moved to the exception list).

(viii) The following is done simultaneously until the total volume of conjugate required is aspirated:

(1) The pipette Z-axis motor is moved down at a speed of "X" steps/second.

(2) The syringe motor aspirates "X" uL at a speed of "X" ul/sec.

(3) The LLS is checked to ensure that the probe is still in the fluid.

(ix) The LLS is deactivated.

(x) The pipette Z-axis is moved up to the Z-clear position.

(xi) The pipette R-axis is moved over the RG incubation vessel.

(xii) The pipette Z-axis is moved downward to the dispensing position within the RG reagent container.

(xiii) The syringe dispenses "X" uL of conjugate at a rate of "X" ul/sec.

(xiv) The pipette Z-axis is moved up to the Z-clear position.

(b) Probe rewash

The probe is washed again to ensure that it is free from contamination as described in Section 6 (Sample Kitting).

9. MEIA Puffer Kitten

(a) The RG carousel is rotated until the RG buffer container is located at the buffer kit station under the MEIA buffer manifold.

(b) "X" uL of MEIA buffer is dispensed into the buffer reservoir at a rate of "X" ul/sec.

F. TRANSFER OF THE RG TO THE PROCESS AREA

1. The RG carousel is rotated into the transfer station.

2. The process carousel is rotated so that the empty position is aligned with the transfer position.

3. The transfer mechanism O-axis is rotated to the sample entry area.

4. The transfer mechanism R-axis grabs the RG and pulls it into the transfer mechanism

5. The transfer mechanism O-axis is rotated so that the RG is aligned with the empty space on the process carousel.

6. The RG is loaded onto the process carousel.

SYSTEM DESCRIPTION OF THE MEIA PROCESS AREA FOR CEA

A. The system waits for the temperature equalization time and evaporation window to expire

B. THE FIRST PIPETTE ACTIVITY (Microparticle/Sample reaction)

1. The incubation timer is set according to the assay file descriptions.

2. MEIA buffer aspirate.

(a) The process carousel is moved so that the RG is at the pipetting station.

(b) The syringe aspirates "X" uL of air at a rate of "X" ul/sec.

(c) The pipette R-axis is moved over the RG buffer container.

(d) The pipette Z-axis is moved down to the upper Z-position above the RG buffer container.

(e) The pipette Z-axis is moved down to the Z-LLS position.

(f) The LLS is activated to ensure that no fluid is currently being detected.

(g) The pipette Z-axis is moved downward at a constant speed until fluid is detected or until the Z-Asp limit is reached (fluid is assumed to be detected).

(h) Based on the Z-height position at which the fluid is detected and the Z-Height/Volume table, the system calculates the volume of fluid in the container and compares it to the volume specified in the pipetting description. If the volume in the container is sufficient, the aspiration sequence is initiated (if the volume is insufficient, the test is aborted and the test request is moved to the exception list).

(i) The following occurs simultaneously until the total volume of MEIA buffer required is aspirated:

(1) The pipette Z-axis motor is moved down at a speed of "X" steps/sec.

(2) The syringe aspirates "X" uL at a rate of "X" ul/sec.

(j) The LLS is checked to ensure that the probe is still in the fluid.

(k) The LLS is deactivated.

(1) The pipette Z axis is moved up to the position above Z.

3. Sample aspirate

(a) The pipette R-axis is moved over the RG sample container.

(b) The pipette Z-axis is moved down to the Z-LLS position.

(c) The LLS is activated to ensure that no fluid is currently being detected.

(d) The pipette Z-axis is moved downward at a constant speed until the fluid is detected or until the Z-Asp limit is reached (fluid is assumed to be detected).

(e) Based on the Z-height position at which the fluid is acquired and the Z-height/volume table, the system calculates the volume of fluid in the container and compares it to the volume specified in the pipetting description. If the volume in the container is sufficient, the aspiration sequence is initiated (if the volume is insufficient, the test is aborted and the test request is moved to the exception list).

(f) The following occurs simultaneously until the total volume of sample required is aspirated:

(1) The pipette Z-axis motor is moved down at a speed of "X" steps/sec.

(2) The syringe aspirates "X" uL at a rate of "X" ul/sec.

(g) The LLS is checked to ensure that the probe is still in the fluid.

(h) The LLS is deactivated,

(i) The pipette Z axis is moved up to the Z erase position.

4. The MEIA buffer and sample are added to the microparticles in the incubation vessel.

(a) The pipette Z-axis is moved down to the distribution position within the RG incubation vessel.

(b) The syringe dispenses "X" uL of MEIA buffer and sample at a rate of "X" ul/sec.

(c) The pipette Z-axis is moved up to the Z-clear position.

5. Probe rewash

The probe is washed again to ensure that it is free from contamination as described in Section 6 (Sample Sealing).

C. CARTRIDGE LOADING (This activity occurs when the equipment is not in use)

1. Move the temporary carousel so that the reserved position is under the feeder device.

2. Cycle the hinged door mechanism to load a flashlight into the carousel.

3. Cycle the lock mechanism to place another MEIA cartridge on the trap door (for the next tab load).

4. Check the incubation timer. If it has expired, start the next pipetting process.

D. SECOND PIPETTE ACTIVITY (transfer of the reaction mixture to the matrix)

1. The incubation timer is set according to the assay file descriptions.

2. Buffer aspirate.

(a) The process carousel is moved so that the RG is at the pipetting point.

(b) The syringe aspirates "X" uL of air at a rate of "X" ul/sec.

(c) The pipette R-axis is moved over the RG buffer container.

(d) The pipette Z axis is moved down to the position above Z.

(e) The pipette Z-axis is moved down to the Z-LLS position.

(f) The LLS is activated to ensure that no fluid is currently being detected.

(g) The pipette Z-axis is moved downward at a constant speed until a fluid is detected or until the Z-Asp limit is reached (it is assumed that the fluid is detected).

(h) Based on the Z-height position at which the fluid is sensed and the Z-height/volume table, the system calculates the volume of fluid in the container and compares it to the volume specified in the pipetting description. If the volume in the container is sufficient, the aspiration sequence is initiated (if the volume is insufficient, the test is aborted and the test request is moved to the exception list).

(i) The following occurs simultaneously until the total volume of buffer required is aspirated:

(1) The pipette Z-axis motor is moved down at a speed of "X" steps/sec.

(2) The syringe aspirates "x" uL of sample at a rate of "X" ul/sec.

(j) The LLS is checked to ensure that the probe is still in the fluid.

(k) The LLS is deactivated.

(l) The pipette Z axis is moved up to the position above Z.

3. Reaction mixture aspirate.

(a) The pipette R-axis is moved over the RG incubation vessel.

(b) The pipette Z-axis is moved down to the Z-LLS position.

(c) The LLS is activated to ensure that no fluid is currently being detected.

(d) The pipette Z-axis is moved downward at constant velocity until fluid is detected or until the Z-Asp limit is reached (it is assumed that the fluid is detected).

(e) Based on the Z-height position at which the fluid is sensed and the Z-height/volume table, the system calculates the volume of fluid in the container and compares it to the volume specified in the pipetting description. If the volume in the container is sufficient, the aspiration sequence is initiated (if the volume is insufficient, the test is aborted and the test request is moved to the exception list).

(f) The following occurs simultaneously until the total volume of the required reaction mixture is aspirated:

(1) The pipette Z-axis motor is moved down at a speed of "X" steps/sec.

(2) The syringe aspirates "x" uL of sample at a rate of "X" ul/sec.

(g) The LLS is checked to ensure that the probe is still in the fluid.

(h) The LLS is deactivated.

(i) The pipette Z-axis is moved up to the Z-clear position.

4. The reaction mixture distribution in the matrix.

(a) The following is carried out simultaneously and together with the reaction mixture aspirate (above):

(i) The temporary carousel is moved so that the cartridge is at the pipetting point.

(ii) The pipette R-axis is moved over the MEIA cartridge (matrix) surface.

(iii) The pipette Z-axis is moved down to the matrix distribution position.

(iv) The syringe dispenses "X" uL of the reaction mixture at a rate of "X" ul/sec.

(v) The system delays for "X" seconds until the reaction mixture has been absorbed by the matrix.

5. Buffer washing of the matrix.

(a) The syringe dispenses "X" uL of buffer at a rate of "X" ul/sec.

(b) The pipette Z-axis is moved up to the Z-erase position.

6. Rinse the probe.

The probe is washed again to ensure that it is free from contamination as described in Section 6 (Sample Kitting).

7. When the incubation timer expires, the next pipette activity begins.

E THIRD PIPETTE ACTIVITY (conjugate addition)

1. The incubation timer is set according to the assay file descriptions.

2. Conjugate aspirate.

(a) The process carousel is moved so that the RG is at the pipetting point.

(b) The syringe aspirates "X" uL of air at a rate of "X" ul/sec.

(c) The pipette R-axis is moved over the RG Reagent 1 (conjugate) container.

(d) The pipette Z axis is moved down to the position above Z.

(e) The LLS is activated to ensure that no liquid is currently detected.

(f) The pipette Z-axis is moved downward at a constant speed until fluid is detected or until the Z-Asp limit is reached (fluid is assumed to be detected).

(h) Based on the Z-height position at which the fluid is sensed and the Z-height/volume table, the system calculates the volume of fluid in the container and compares it to the volume specified in the pipetting description. If the volume in the container is sufficient, the aspiration sequence is initiated (if the volume is insufficient, the test is aborted and the test request is moved to the exception list).

(h) The following is done simultaneously until the total volume of conjugate required is aspirated:

(i) The pipette Z-axis motor is moved downward at a speed of "X" steps/sec.

(ii) The syringe aspirates "x" uL of sample at a rate of "X" ul/sec.

(i) The LLS is checked to ensure that the probe is still in the fluid.

(j) The LLS is deactivated.

(k) The pipette Z-axis is moved up to the Z-clear position.

3. Conjugate distribution (performed simultaneously). (a) The temporary carousel is moved so that the cartridge is at the pipetting point.

(b) The pipette R-axis is moved over the cartridge (matrix) surface.

(c) The pipette Z-axis is moved down to the matrix distribution position.

(d) The syringe dispenses "X" uL of conjugate at a rate of "X" ul/sec.

(e) The pipette Z-axis is moved up to the Z-clear position.

(f) Wait "X" seconds until the reaction mixture is removed from the Matrix was absorbed.

4. The probe-washing.

The probe is washed again to ensure that it is free from contamination as described in Section 6 (Sample Kitting).

F. RG UNLOADING (This activity takes place when no equipment is in use)

1. The following is done simultaneously:

(a) The process carousel is rotated so that the empty space is at the transfer station.

(b) The transfer mechanism O-axis is moved to the process carousel.

2. The RG is gripped by the transfer mechanism R-axis and pulled into the transfer mechanism.

3. The transfer mechanism O-axis is rotated so that the RG is aligned with the waste container.

4. The RG is pushed into the waste container.

5. Check the incubation timer. When it expires, start the next activity.

G. MEIA READING PREPARATION

1. The lamp intensity is changed from the idle state to the burning state.

2. The PMT gain is adjusted.

H. MATRIX WASHING PROCESS

1. The temporary carousel is rotated so that the cartridge is located at the matrix washing station.

2. Repeat the following steps until all of the buffer specified in the assay file for the cartridge wash has been dispensed.

(a) "X" uL of heated MEIA buffer are distributed on the matrix in 50u1 cycles at a rate of "X" ul/sec.

(b) Wait "n" seconds.

I. MUP DISTRIBUTION

1. The temporary carousel is rotated so that the cartridge is located at the MUP station.

2. 50 μl of heated MUP is distributed on the matrix at a rate of "X" μL/sec.

3. Wait "n" seconds.

J. MEIA READING PROCESS

1. The temporary carousel is rotated so that the cartridge is at the reading station.

2. The following steps are repeated until the number of micro-reads specified in the assay file have been performed (usually 8)

(a) Read "X,XX" seconds.

(b) Wait for "X,XX" seconds.

3. The reader is returned to its rest position. (a) The lamp intensity is set to the rest position.

(b) The PMT gain is adjusted.

4. The raw readings are converted by the optics microprocessor into standardized readings (light intensity/lamp intensity hitting the detector).

5. A speed is calculated from the standardized readings in relation to time by the system.

6. For quantitative assays, the rate is inserted into a calibration curve to provide a concentration result.

7. For qualitative assays, the sample velocity is compared to an index or cut-off velocity to determine whether the sample is positive or negative (or reactive or non-reactive).

K. CARTRIDGE UNLOADING (This activity occurs when the equipment is not in use)

1. The temporary carousel is rotated so that the Cartridge is at the ejection station.

2. The ejector is cycled to guide the cartridge into the waste container.

Schematic reaction sequences are set forth in Figures 26, 27 and 28 which are typical of assays that can be handled by the automated analytical immunoassay system of the invention. In Figure 26, a T4 assay, FPIA sequence 420, is shown wherein in step 1, T4 bound by thyroxine binding protein (TBP) 424 is reacted with a T4-splitting agent 426 to yield TBP 428 plus unbound T4 (430). In step 2, T4 (430) is added to T4 antibody 432 yielding a reaction product 434 (T4 antibody-T4 complex). In step 3, the T4 antibody-T4 complex 434 is treated with T4 indicator (fluorescent) 436, which yields a measurable fluorescent polarization reaction product 438.

In Figure 27, a schematic reaction sequence 440 for a 1-step sandwich MEIA (ferritin) determination is shown. In steps 1 and 2, an alkaline anti-ferritin phosphatase conjugate is mixed with a ferritin sample 444 and anti-ferritin microparticles 446 to provide a ferritin antibody-antigen-antibody complex 448. In step 3, the antibody-antigen-antibody complex 448 is reacted with 4-methylumbelliferyl phosphate (MUP) 450 to yield methylumbelliferone (MU), which is fluorescent. The rate of MU generation is measured. In Figure 28, the schematic reaction sequence 456 for a 2-step sandwich MEIA for the HTSH sample is provided. Anti-HTSH specific microparticles 458 are added to the HTSH sample 460, providing a reaction product HTSH antibody-antigen complex 462. In steps 2 through 4, the complex 462 is combined with an anti-HTSH alkaline phosphatase 464, resulting in an HTSH antibody-antigen-antibody complex 466. In step 5, the complex 466 is reacted with the MUP 450 to yield MU that is fluorescent. The rate of MU generation is measured. In accordance with embodiments, the automated analytical Immunoassay system provides an instrument, software, hardware and process technology to continuously perform a variety of assays with random access available to the operator. The use of carousel pipetting technology for kitting and pipetting operations on either the main carousel or the process carousel depending on the test being planned provides unprecedented planning flexibility. The inventive system allows for joint kitting and pipetting for both immunodepletion and competitive immunoassay technologies, which use a common main carousel, transfer station, first kit and pipetting probe and process carousel and second pipetting probe before dividing for the respective instrument and process requirements. Also jointly shared is the disposal device and supply of materials as well as a common computer network for scheduling, testing, kitting and pipetting.

It will be appreciated that several assays can be performed with minimal operator input or manipulation of the system, and that the system can be used for other methods and assays not immediately discussed but which will be readily apparent to one skilled in the art in view of the above invention disclosure and claims. It will also be appreciated that, although specific embodiments of the present invention have been disclosed, various changes and adaptations can be made to the apparatus and methods without departing from the teachings of the specification and the scope of the invention as set forth in the appended claims.

If technical features in the claims are provided with reference signs, these reference signs are only present for the purpose of better understanding of the claims. Accordingly, such reference signs do not represent any limitations on the scope of protection of such elements which are only identified by such reference signs as an example.

Claims (12)

1. A method for producing a plastic analysis cuvette (506) for the optical analysis of a liquid test sample, the method comprising the following steps: (a) providing a means (500) for molding the plastic analysis cuvette (506), the means (500) for molding comprising a mold cavity (508) having an upper end (510) and a lower end, wherein an optical reading region (516) of the plastic analysis cuvette (506) is formed at approximately the lower end of the mold cavity (508); (b) injecting a molten plastic material at the upper end (510) of the mold cavity (508); (c) allowing the plastic melt material to substantially solidify; (d) removing the molded plastic analysis cuvette (506) from the molding means (500), wherein the plastic melt material is injected into the mold cavity (508) at a sufficient distance from the optical reading area (516) so that the birefringence of the optical reading area (516) has a birefringence corresponding to that of a glass analysis cuvette. 2. The method of claim 1, wherein the molten plastic material is injected into the mold cavity (508) from at least two locations (512, 514) at the upper end (510) of the mold cavity (508). 3. A method according to claims 1 or 2, wherein the mold cavity (508) is cylindrical. 4. A method according to claims 1 or 2, wherein the mold cavity (508) is rectangular. 5. A method according to claims 1 or 2, wherein the mold cavity (508) is square. 6. The method of one or more of claims 1-5, wherein the means (500) for molding the plastic analysis cuvette (506) comprises a mold (502) for receiving a mold core (504) with the mold cavity (508) formed therebetween. 7. A method according to one or more of claims 1-6, wherein the plastic melt material is selected from the group consisting of acrylic, polystyrene, styrene acrylonitrile and polycarbonate. 8. The method of one or more of claims 1-7, wherein the plastic material is injected at a time rate of between about 0.90 seconds and about 1.40 seconds. 9. The method according to one or more of claims 1-8, wherein the plastic material is held in the molding means (500) for between about 1.75 seconds and about 2.25 seconds and wherein the plastic material is held in the molding means (500) at a pressure of between about 50% of the injection pressure and about 80% of the injection pressure in the molding means (500). 10. The method of one or more of claims 1-9, wherein the plastic material is injected at a pressure of between about 896.3188 x 10⁴ Pa (1300 PSI) and about 1103.1616 x 10⁴ Pa (1600 PSI). 11. The method of one or more of claims 1-10, wherein the temperature of the plastic material injected into the molding means (500) is between about 215.55°C (420°F) and about 237.77°C (460°F). 12. The method of one or more of claims 6-11, wherein the temperature of the mold cavity (508) is maintained at a temperature of between about 37.77ºC (100ºF) and about 59.99ºC (140ºF) and the temperature of the mold core (504) is maintained at a temperature of between about 15.55ºC (60ºF) and about 37.77ºC (100ºF).